What is the purpose of clothing? How does this relate to tzeniut? What does halakha say about dress?
Click here to view an updated version of this shiur with additional features on the Deracheha website.
Did you know there's more to Deracheha than our shiurim? Sign up for our newsletter here and get all our content!
Have some feedback for us? Please click here!
By Laurie Novick
Rav Ezra Bick, Ilana Elzufon, and Shayna Goldberg, eds.
What is the purpose of clothing?
A textual look at the reasons why we wear clothes provides insight into the halachot of clothing.
The history of clothing begins in the Bereishit story, when Adam and Chava move from an innocent, animal-like nakedness to a more aware, distinctively-human clothedness. They make this transition in two stages.
First, upon eating from the Tree of Knowledge, Adam and Chava become aware that they are naked, and cover their nakedness with fig leaves:
And the eyes of both of them were opened and they knew that they were naked and they sewed a fig leaf and made themselves loincloths.
Second, God dresses them more fully to prepare them for the exile from Gan Eden and the ensuing responsibility to build civilization:
And God made Adam and his wife cloaks of skins and dressed them.
What is the purpose of these two types of clothing? Rav Aharon Lichtenstein suggests looking at a second pair of verses about clothing, this time regarding the priestly garments.
Shemot 28:40, 42
And for the sons of Aharon, make tunics and make them belts and make them turbans, for honor and for glory….And make them pants of cloth to cover the flesh of their nakedness. They will be from their loins until their thighs.
wear four priestly garments, without which they are unfit to serve in Beit Ha-mikdash
These include outer garments are for "honor and glory," as well as pants to cover their nakedness. Rav Lichtenstein explains the significance of this duality in Bereishit
Rav Aharon Lichtenstein, Fig Leaves and Coats of Skins (translated by Kaeren Fish)
Adam and Chava sewed for themselves only fig leaves: they were ashamed of their sin, but did not comprehend fully the profundity of its significance…They made loincloths to cover their nakedness, but did not prepare new clothes. By clothing them in coats of skins, God brought them up to a new level: the garments gave them honor and beauty; it changed them and transformed them into new people…The primal, natural man who served God with tranquility, fully integrated in nature, was replaced by historical, cultural man – a completely different creature in terms of both his personal standing and his relationship with nature.
We can identify here, then, two primary functions of clothing: a basic function of covering nakedness, and a more elevated function of dignifying and glorifying the human being.
These functions of clothing connect to our discussion
of complementary approaches to the concept of tzeniut
: a physically-oriented approach and a principle-oriented approach.
The need to cover erva corresponds directly to the more physical aspect of tzeniut. By being physically modest, we draw a fundamental distinction between the human and the animal.
Dressing for honor is an expression of a more principle-oriented approach to tzeniut, which culminates in a culture of respect for others and personal dignity. We apply the principle of tzeniut to dress by dressing in a manner that honors our identity, commitments, and contexts. The Jewish people are a "mamlechet kohanim," a kingdom of kohanim" (Shemot 19:6).
A Range of Functions
Clothing serves a range of other functions as well, from the personal to the social and even the national spheres.
Physically, we need the coverage of clothing to protect us from the elements. The Eishet Chayyil
, for instance, sees to it that her family is protected from snow.
Among women, this principle finds halachic expression in the basic, Torah-level obligation of a husband to provide his wife with clothing appropriate for different types of weather:
We obligate him to give her clothing fit for the rainy season and the sunny season, at least what every mistress of a household in that land wears….
So, too, we obligate him to give her adornments, like colored garments to wrap her head and her forehead…
Beyond the basics, Rambam teaches that the wife also has a right to clothing that will beautify her.
Along these lines, while the Eishet Chayyil
teaches that true beauty is within, she still takes care to dress well:
Mishlei 31:22, 25
…Linen and purple are her clothing… Strength and glory are her clothing and she laughs to the last day…False is grace and vain is beauty; a woman who fears God, she will be praised.
Dressing in beautiful clothing is not a lack of tzeniut for her, or anyone, any more than it is for the kohanim. Tzeniut is relevant in determining what type of beauty will dignify her, maintaining the proper balance between physical and spiritual. The Eishet Chayyil seems to get this right. Ultimately her clothing, at least metaphysically, is a manifestation of strength and honor.
Similarly, Rambam writes that dressing nicely is particularly important for a talmid chacham, whose honorable dress can help his Torah become beloved and sanctify God's name:
Rambam, Mishneh Torah, Laws of De'ot 5:9
The dress of a scholar is attractive and clean…
There is no contradiction between dressing as a Jew should and dressing well. Beautiful dress is a sign of self-respect.
What about dressing for self-expression?
While dressing for self-respect is well attested in classic sources, we are unaware of clear examples of dressing for self-expression in Tanach or rabbinic sources. Perhaps this is because people did not have a wide range of clothing to choose from in pre-industrial eras, which limited the possibility of dressing for self-expression.
We do find some support for the idea that clothing can help shape our sense of self. When Esther prepares to enter Achashverosh’s throne room uninvited, she “dresses in royalty.”
And it was on the third day and Esther dressed in royalty and she stood in the inner courtyard of the king’s house, across from the king's house.
Certainly, Esther needs to appear at her most regal before the king and his court. Yet her attire also may influence her own inner world and self-perception, building self-confidence as she approaches this critical encounter.
Changing our clothing can affect our inner reality. Esther's clothes help show her – as well as others – that she is a queen.
A central element of a tzanu'a approach to using clothes for personal ends is to put them in service of the soul. In an interview, Gila Manolson extends this idea to the current idiom of using clothes to express "who we really are."
Gila Manolson, "Does Tznius Mean Invisible?" Times of Israel, August, 2019
Tznius means getting beyond the superficiality that is all too pervasive in our world, and instead defining ourselves by who we truly are inside, at the essential level — our soul. It then means using our dress and behavior to project this “I am a soul” message outward, thereby encouraging others to relate to us for who we really are.
In the social context, clothing is a means of signaling status to others, and a way to treat shared space with respect.
Dress gives others an indication of our social or professional status, as when we dress for a job interview, or when Par'o clothes Yosef in kingly attire as a prelude to granting him the role of viceroy.
We can even manipulate others' perceptions of us through how we dress, playing on their biases, as when Ya'akov wears Eisav's clothing in order to receive his beracha
When dressing, we inevitably send messages to others about ourselves.
Clothing also conveys a message about our relationship to a specific person or locale. The Talmud teaches that through dress, we show others something about how we perceive them:
It was taught in the Beit Midrash of Rabbi Yishmael: The Torah teaches you proper conduct. The clothes in which he cooked a pot for his master, he should not wear when mixing [and serving] his master's drink.
When we value people or a social encounter, we dress appropriately for them. We can apply this idea to places as well as to people. For example, Achashverosh's palace is off limits to someone dressed in mourning.
And Mordechai knew all that had been done and Mordechai tore his clothing and dressed in sackcloth and ashes and went out within the city and cried out a great and bitter cry. And he came up to the front of the king's gate, because one cannot come into the king's gate in sackcloth.
To honor the king and his court, one must dress respectably in the palace. Mordechai's sackcloth makes a statement throughout Shushan, but cannot be worn within the palace gates.
Collective norms of dress in a given place help shape its identity. Dressing in accordance with those norms demonstrates respect for that identity.
Clothing also associates us with a social group, through official uniforms or less official shared styles. On a national level, Tzefanya talks about the punishment to befall those Jews who wear the clothes of the nations, indicating that Jews have a unique national mode of dress:
And it will be on the day of God's sacrifice and I will visit punishment on the princes and on the king’s sons and on all those who wear the clothes of the foreigner.
Tzefanya's reference to Jewish and non-Jewish dress may have precursors in the Torah, with halachic implications. During the difficult years of bondage in Mitzrayim, the children of Israel "became a nation there" (Devarim 6:25). Midrash Lekach Tov lists the defining factors which distinguished us even when we were dominated by another nation:
Pesikta Zutreta, Devarim 46a
"And they became there a nation": This teaches that Israel stood out there. For their clothing and their food and their language were different from the Egyptians'. They were singled out and it was known that they are a nation unto themselves apart from the Egyptians.
The first item in the list is clothing. One ways Jews have set themselves apart as a people is through dress. Interestingly, in parallel versions of this midrash, clothing does not appear, but refraining from exposing erva
or violating the rules of prohibited relations does.
Perhaps the distinctive quality of Jewish clothing is related to covering erva
If Judaism is about working on our internal selves, why do we attribute so much meaning to clothing, which is external?
Although we strive to be spiritual beings, we do live in a physical world, where the first thing we notice about people is typically how they look.
How might dress shape our perceptions at first glance? When everyone in the room is dressed up for Shabbat or for a wedding, it feels like a special occasion. When soldier in uniform boards a bus in Israel, passengers might feel safer. If someone wears flip-flops to a meeting with the President at the White House, a flippant attitude comes through.
We no longer inhabit Gan Eden. There, the body was not a distraction from the soul. In our current reality, it can be. Our clothing gives others insight into who we are, the community we associate with, our tastes, the mood we are in, or the events we will participate in, even without having a direct interpersonal interaction.
By carefully choosing what to emphasize, we can use clothing to redirect social interactions away from externals.
Sarah Alevsky, quoted in "Orthodox Jewish Women Find New Ways to be Fashionable in Crown Heights":
I use the analogy of a Tiffany lamp--you are muting the light because you are putting a stained glass shade on it and the light is being transmitted in many different colors. The same thing happens when you are tznius--you are ‘covering your light’ and there is not a naked glare of what’s there...there are other parts of you that get to express themselves as well.
When we dress, we should take our values into account, and carefully consider what messages we wish to send.
Many of the functions of clothing we've explored are foundational to the halachic discussion of clothing. Let's look at how they translate into Halacha.
Halacha of Covering Erva
The halachic approach to covering nakedness begins with a verse in Devarim
For the Lord your God walks in the midst of your camp to deliver you and to give up your enemies before you, so your camp shall be holy, that He not see in you any matter of nakedness, and turn away from you.
In this verse, dress helps to create an atmosphere of holiness in the camp. Our sages understand the verse as prohibiting men or women from uttering God’s name in the presence of an ervat davar
, a matter of nakedness. They teach that erva
here refers to exposed genitalia,
and then expand the meaning of erva
on a rabbinic level, to take into account more interpersonal factors. (We’ll look at that in our next installment of this series.)
Because of anatomical differences, halacha distinguishes between the erva
of men and of women. A man must clothe his protruding genitalia when he recites berachot
, both to cover it and to ensure that there is a barrier between his heart and his erva
In contrast, the fundamental halacha is that a woman may recite berachot naked, as long as she sits in a manner which conceals her genitalia and buttocks:
A woman sits and separates her challa while naked because she can cover her face [euphemism for genitalia] in the ground, but a man cannot. Rav Nachman bar Yitzchak explained it: As when her 'face' was lowered onto the ground.
Even outside of ritual moments, Jewish men typically wear belts or some sort of garment with a waistband. For women, Ezra Ha-Sofer made a special enactment to wear a sinar:
Bava Kama 82a
Ezra made ten enactments…That a woman should gird herself with a sinar [Rashi: like little pants] out of modesty.
According to Rashi, the sinar
is a set of knickers, designed to ensure that a woman's erva
is not exposed.
Rambam explains that the sinar
should be worn at all times, even in private:
Rambam, Mishneh Torah, Laws of Ishut 24:13
Ezra enacted that a woman should gird herself in a sinar always within her home out of modesty.
This fits in with the ideal that, even in private when not performing rituals, we should all be aware of God's presence, and the pious should minimize nudity as a result:
Shulchan Aruch OC 2:1-2
He should not put on his robe when he is sitting but rather he should take his robe and bring his head and arms into it when he is still lying down. Thus when he gets up he will be covered. One should not say: Here I am in my private chamber; who sees me? For God – “the whole earth is filled with His honor” (Yeshaya 6:3).
How much do we need to cover when in private? Rav Moshe Feinstein articulates a standard of dress in private for the average person; those who wish to be unusually pious may aspire to more.
Responsa Iggerot Moshe YD III 68:4
…It is not among the prohibitions but a virtue, and the reason for taking care to be clothed even in private is "I have placed God before me"…Here the correct measure is like someone sitting in his room before people whom he does not need to honor, but before whom he does not wish to be contemptible. If he feels discomfort because it is too hot for him or some other reason, he is permitted to go [with less clothing]. With this, there is not even an ideal of extra piety, for thus when he is in discomfort, it is accepted to sit this way before people who know of his discomfort – and God knows his discomfort. But revealing erva is prohibited.
To establish proper models of coverage for a private space for the average individual, Rav Moshe compares the situation to a social sphere. Under ordinary circumstances, even before God, we need only be careful to go about covered in a way we would not be embarrassed for average people to see, were they to be in our home. When it is very hot, for example, if we would be comfortable being seen by another in something flimsy, that is acceptable in private.
There's no indication in his words that the standard here should be different for men or women, except that the specifics of their normative dress might differ, and a woman might dress at home as she'd be comfortable being seen in the presence of another woman.
Halacha of Dat Yehudit
The second essential function of clothing, dressing for honor and personal dignity, connects to a halachic category of Jewish women's modest practices including dress, called dat Yehudit:
Rambam, Mishneh Torah, Laws of Ishut 24:11
What is dat Yehudit? The modest [tzeniut] behavior that the daughters of Israel have practiced.
All Jews are expected to act with tzeniut
, and all Jewish women are expected to observe dat Yehudit
. For a married women, behavior that violates dat Yehudit
is considered especially inappropriate, because it might lead to suspicion of extramarital activity, dishonoring the marriage covenant.
According to the mishna, a married woman forfeits her ketuba
(marriage contract) for violating dat Yehudit
Mishna Ketubot 7:6
These [women] exit [marriage] without a ketuba: One who violates dat Moshe or Yehudit.
There is no other recorded penalty for violating dat Yehudit
, because it is a binding social custom, not a classic prohibition.
Classic sources list few specifics of dat Yehudit
, and fewer still with relevance for clothing. Presumably, this is because, as Rashi suggests, dat Yehudit
has traditionally been communicated mimetically (by social imitation), not textually.
Rashi Ketubot 72a s.v. Dat Yehudit
That which the daughters of Israel practiced, even though it is not written down.
Customs can be halachically binding even when they are not written down, but it can be difficult to determine their parameters. Early halachic authorities do not discuss explicitly whether dat Yehudit can change depending on place and time. In a responsum from the early 1950's, Rav Moshe Feinstein writes that dat Yehudit is binding and that violating it is prohibited, but that specifics may be contingent on time and place:
Iggerot Moshe EH I:69
But there is another prohibition for women from the law of dat Yehudit, that they not behave immodestly, in Ketubot 72a. But this aspect is only [a prohibition] when just she personally behaves thus. But when all the women in her city behave this way, it is not applicable to consider this “immodesty”…In any case, since this is how they dress and go about, one should not consider this an act of immodesty and prohibit them, but rather it [a high standard of modesty] is a matter of extra piety and modesty and a blessing will come upon them.
On this view, dat Yehudit halachically obligates women to follow community modesty norms, but those norms are variable.
However, one can argue differently, as Chafetz Chayim does.
Rav Yisrael Meir Ha-Kohen, Geder Olam, Chapter 1
Dat Yehudit is that which the Jewish people practiced always and took upon themselves to be careful with, due to tzeniut. This matter and the like are included in what the verse says, "Do not abandon the Torah of your mother" (Mishlei 1:8).
According to the Chafetz Chayim, those aspects of conduct known as dat Yehudit
that did receive explicit mention in early rabbinic literature are permanently binding, irrespective of practice.
Halacha of Dress for Prayer
Dressing in order to communicate respect for a given setting also finds expression in Halacha. On a basic level, a full four of our daily birchot ha-shachar can be understood to refer to aspects of clothing. Birchot ha-shachar reflect our gratitude for how God has ordered our world, and clothing is essential to assuming our role in the world each day as God's servants.
Although we always inhabit God's world and live in God's presence, we more consciously meet with God when we pray. The Talmud provides precedents for dressing up to prepare for the encounter with God in prayer:
Rava son of Rav Huna put on stockings and prayed. He said, "Prepare to meet your God, Israel" (Amos 4:12).
For Rav Huna would metzayyen himself [Rashi: adorn himself with his clothing] and then pray.
Based on these passages, Rambam details halachic guidelines for appropriate dress for prayer, and Shulchan Aruch
Rambam, Mishneh Torah, Laws of Tefilla 5:5
[The person praying] arranges his clothes first and adorns himself and then goes back [to pray], as it is said, "Bow down to God with the glory of sanctity." He should not stand in prayer [shemoneh esrei] while wearing his wallet and not with a bare head and not with bare legs, if the way of the people of the place is to stand before important people only with stockings.
The parameters of appropriate dress for prayer can vary depending on the customs of a given place. The reference point for dignified clothing is social and somewhat subjective. Thus, some synagogues insist that the person leading the prayers on Shabbat must wear a jacket and tie, because that is considered dignified clothing. In some comparable communities in Israel, however, where a jacket and tie aren’t the norm for formal meetings, they are not worn for prayer.
A person can change clothes before or after prayer (like putting a jacket on or taking it off), and prayer is fully valid if, in a pinch, a person has to pray when not dressed as would be ideal for meeting an important person. However, shacharit and mincha come at different times during the day, and many of us could not change clothes multiple times a day even if we wanted to. When we dress for the day, we should consider how we wish to appear as we stand before God in prayer.
Halacha of Jewish Dress
Another social function of dress, expressing affiliation, connects to the mitzva not to follow the ordinances of idolaters:
Like the deed of the land of Egypt where you dwelled, you shall not do, and like the deed of the land of Canaan where I am bringing you, you shall not do, and you shall not go according to their ordinances. You will do my laws you will do and keep my ordinances, to go in them. I am the Lord your God.
A midrash halacha suggests that one example is not to dress like idolaters just for the sake of imitating them:
Sifrei Devarim 81:30
That you not say, since they go out with a basket, I too will go out with a basket; since they go out in purple, I too will go out in purple; since they go out in sandals, I too will go out in sandals.
What does this mean on a halachic level? Maharik writes the essential responsum on this topic, to address whether halacha would permit Jewish medical students of his day to wear a uniform called a kafa or whether doing so would be a violation of u-v-chukoteihem lo teileichu. He writes that the prohibition of dressing like gentiles applies specifically where there is an element of immodesty:
Responsa Maharik 88
According to what has been mentioned in my opinion, one should prohibit due to "ordinances of the non-Jews" that which the non-Jews practice if it involves any slight breach of the bounds of modesty and humility; also this is prohibited. And if the halacha is according to the Tana [sage] of the baraita of Sifrei, who taught that one should not say 'Since they go out in purple, I too will go out in purple; since they go out in sandals, I too,’ etc. For these statements are arrogant and haughty and Ya'akov's portion is not in them. Rather the matters of Israel and their path is to be modest, “and the meek [who] will inherit the earth,” and not to turn to haughtiness. It appears that even this applies specifically when one does so [wears immodest clothing] to resemble them [the non-Jews] and not for a known purpose, as the language implies "Since they wear it, I too will…"
On this view, wearing immodest clothing just because non-Jews have popularized it is a Torah-level prohibition.
Rav Moshe Feinstein clarifies that in the modern Western world, the prohibition does not apply in full force, since the non-Jews among whom we live are not idolaters and since, in practice, many Jews themselves wear immodest clothing. Even so, he points out that women's clothing in particular is often deliberately designed to be immodest, and argues that immodesty may inherently define clothing as non-Jewish.
Responsa Iggerot Moshe YD I:81
But the really immodest fashions that were recently instituted in women's clothing – in our great iniquity, since Jewish women also wear them, we should not consider them non-Jewish dress from the perspective of the clothes themselves. But from the perspective of immodesty, perhaps one should consider them among the ordinances of the idolater. In any case, one should prohibit these clothes to Jewish women, not only because of the matter of immodesty on its own terms but also as non-Jewish dress….When it comes to really immodest clothing, it is possible that even without Jewish women having the custom to avoid them, they should be prohibited. One must look into this prohibition more closely. But in practice, one should certainly prohibit these clothes to women on the basis of their immodesty in itself, even if we say they do not entail the prohibition of non-Jewish dress….
Rav Moshe suggests that immodest clothes are prohibited regardless of whether they are considered non-Jewish dress, because they break the boundaries of tzeniut.
Do I have to dress frum? Is there a halachic problem with dressing in style?
Many of us can spot a frum Jew from a mile away. Sometimes, we might have mixed feelings about looking like one. It is natural to feel some tension between wanting to be part of the group and wanting to be an individual.
Dressing frum can be a positive opportunity, a way to signal to ourselves and to others at a glance that we are proud to count ourselves among the community of shomerei mitzvot.
There can be a distinction, though, between dressing in line with Halacha and looking frum. Sometimes clothes that are widely accepted in the frum community actually don't seem as modest as other clothing. That should give us pause.
The halachic discussion of chukot ha-goyim does not seem to obligate us to look specifically Jewish. Wearing something stylish, as long as it is modest and dignified, is permissible. Rather, we should not adopt immodest clothing styles, nor should we follow senseless clothing trends just to fit in with non-Jews. It is one thing to be stylish, quite another to be a fashion victim.
For example, a cozy 'Christmas sweater' would not be a problem, as long as it does not have symbols directly associated with Christmas (e.g., snowmen are permissible).
Most important, we should ask ourselves how we choose whom to emulate, and be particularly wary of trends that emulate specific figures associated with immodesty (or, though less common today, idolatry). Members of our own community would ideally provide inspiration. Outside the Jewish community, the Duchess of Cambridge would be more the type to emulate than most pop singers. Dressing in styles from India could also be permissible, to a point, if they appeal to us. Here, concerns about chukot ha-akum and cultural appropriation probably converge.
Thanks to the wide variety of clothing styles available, we have room for balancing modest individualism with a sense of fundamentally belonging to the tribe.
When Jews consider how to dress, we need to keep in mind the range of personal, social, and national functions that clothing serves. Dressing in accordance with tzeniut means more than covering up. It means being sensitive to context, and it means dressing in a way that honors our God, our people, and ourselves.
Specific halachot that reflect the principle of tzeniut include Jewish dress, dat Yehudit, dressing for prayer, and the laws of covering erva. Many of these aspects of Halacha are equally relevant to women and men.
We all should be cognizant of the significance of clothing. Men and women need to think about what constitutes dignified dress, and how our attire creates and affects the atmosphere we inhabit. We need to consider and address broad questions of what kind of environment creates holiness, what clothing is appropriate for a particular situation, and what image of ourselves we want to project when we get dressed.
Although, inevitably, halachic discussion of dress with regard to women gets into questions of what and how, as we discuss in the next installment of this series, these are not the most essential questions for us to consider. Most of the "exactly how much" discussion becomes moot when our choices are value-driven and take the norms around us into account.
- Ellinson, Rabbi Elyakim Getsel. Woman and the Mitzvot: Guide to the Rabbinic Sources Vol. 2, The Modest Way, trans. Raphael Blumberg. Jerusalem: World Zionist Organization Department for Torah Education and Culture in the Diaspora, 1992.
- Haber, Rav Shemuel. Et Tzenu’im Chochma, Vol. 1. Karnei Shomron, 2007.
- Henkin, Rav Yehuda. Understanding Tzniut. Jerusalem: Urim Publications, 2008.
And they [the priestly garments] shall be upon Aharon and upon his sons when they come into the Tent of Meeting or when they approach the altar to serve in holiness, so that they not bear iniquity and die, This is an eternal ordinance for him and for his seed after him.
Her household will not fear from snow because all of her household is dressed in silks.
If he takes himself another [wife], he may not reduce her food, her clothing, or her marital relations.
Similarly, a classic way for a woman to fulfill the mitzva of simchat Yom Tov
is through purchasing and wearing fine clothes:
Rabbi Yehuda says: Men [observe simchat Yom Tov] with what is fitting for them, and women with what is fitting for them. Men with what is fitting for them, with wine. And women with what? Rav Yosef taught: In Bavel, with colored clothing, in Eretz Yisrael with pressed linen clothing.
And Par'o removed his ring from his hand and put it upon the hand of Yosef and he dressed him in linen garments and put the golden collar on his neck. And he had him ride in the chariot of the second in command that he had and they called before him "kneel," and he placed him over all the land of Egypt.
And Rivka took the precious clothes of Eisav her older son, that were with her in the house, and she dressed Ya'akov her younger son.
Perhaps for this reason the verse's word for clothing, beged, shares a root with the Hebrew word for betray, bagad.
 Vayikra Rabba Emor 32
R. Huna in the name of Bar Kappara: On account of four things Israel were redeemed from Egypt, because they did not change their names and did not change their language, and because they did not speak lashon ha-ra, and because there was no promiscuous sexual conduct (perotz erva) among them.
Mechilta Bo Masechta De-Pischa 5
Rabbi Eliezer Ha-kappar in the name of Rebbi says: And didn’t Israel have in hand four mitzvot that all the world did not achieve? Namely, that they were not suspected of illicit sexual conduct (erva), and not of lashon ha-ra, and they did not change their names, and they did not change their language.
We discuss some of the more hashkafic implications of this verse in our piece on tzeniut
It is written, “That He not see in you any matter of nakedness.” This [verse] is necessary in accordance with the view of Rav Yehuda, for Rav Yehuda said: If an idolater is naked, it is prohibited to recite Shema in his presence. Why specify an idolater? Even a Jew also [is included in the prohibition].
Sefer Yere’im 392
The meaning of erva is that place [a euphemism for genitalia] of a man or woman, as it is written, “you shall not reveal the erva of your sister.”
Shulchan Aruch OC 70:4
It is prohibited to recite [Shema] facing erva.
Mishna Berura OC 70 s.k. 19
Facing erva – as it is written, “For the Lord your God walks in the midst of your camp to deliver you and to give up your enemies before you, so your camp shall be holy, that He not see in you any matter of nakedness”… From here the Sages learned that wherever God walks with us, that is, when we are occupied with reciting Shema and tefilla or with words of Torah, we need to be careful that God will not see in us any matter of nakedness, that is, that nakedness should not be in front of a person who is reciting [Shema] or praying, within his sight… and similarly that he should not be naked then, for through this one sees that his own nakedness is also included in this verse.
 Shulchan Aruch OC 91:1-2
If the garment was belted around his waist and covered him from his waist down, it is forbidden to pray (shemoneh esrei) until he covers his heart. And if he did not cover his heart, or unavoidably had nothing to cover it with, since he covered his erva and prayed, he has fulfilled his obligation…but other berachot, it is permissible to recite without a belt, since he has pants. Rema: And his heart does not see his erva.
Alternatively, it may have been an apron atop her clothing, or even a means of maintaining menstrual hygiene:
Shita Mekubetzet Bava Kama 82a
Sinar – that women are accustomed to gird over their loins. At the time of their menses in order that their clothes not be soiled from the menses and [menstrual blood] not reach the floor.
See also Iggerot Moshe
YD III 47:3. There he makes it clear that this ruling applies also to women.
Dat Yehudit causes forfeit [of the ketuba] because of brazenness and because of the concern of adultery.
Tosafot Rid Ketubot
Meaning, something that is not forbidden but regarding which the women have adopted modest practice.
Shulchan Aruch OC 91:5
One should not stand to pray while wearing his wallet and not with an exposed head and not with bare legs, if the way of the people of the place is to only stand before important people with long trousers.