The Mitzva to Eat Matza and the Measurement of a Kezayit (1)

 

Translated by David Silverberg 

I.      The Mitzva to Eat Matza Nowadays

 

     The Gemara in several places posits that the obligation to eat matza Pesach night constitutes a Biblical obligation, even in the post-Temple period.  The Gemara in Pesachim (120a) notes that the Torah's requirement that the korban Pesach (Paschal offering) be eaten "with matzot and marror" appears to suggest that the obligation to eat matza and marror directly relates to the mitzva of korban Pesach.  One would perhaps conclude, then, that in the absence of the Bet Hamikdash, when the Paschal sacrifice is not offered, no Biblical requirement to eat matza and marror exists.  As the Gemara notes, however, although this conclusion is correct insofar as marror is concerned, "matza - the verse repeated it [its obligation]: 'in the evening you shall eat matzot.'"  This additional verse obligates the consumption of matza "in the evening" of Pesach, regardless of the offering of the korban Pesach.  (Other derivations of this obligation appear in Pesachim 28b and Kiddushin 37b.  Tosafot in Kiddushin and Maharam Chalawa in Pesachim 28b address the issue of why the Gemara needs multiple sources for this single halakha.)

 

     The Chatam Sofer writes (Shu"t Chatam Sofer, CM 196, "hashmatot"):

 

The positive requirement to eat "matza shemura" on Pesach night is the only one of all the mitzvot requiring eating in the entire Torah that remains!  We have no Pesach, sacrifices, teruma or ma'aser sheni - only one mitzva [of eating] that applies annually.  And if even this one is not fulfilled completely... will this be pleasing in God's eyes, Heaven forbid?

 

In other words, the mitzva of eating matza is the only mitzva involving eating that remains obligatory on the Biblical level nowadays, and as such one must be particularly scrupulous in his observance thereof.

 

II.   The Amount of Matza Required for the Mitzva

 

     The Rosh writes (Hilkhot Pesachim, printed at the end of Masekhet Pesachim, towards the bottom of 135 in the Vilna edition; Shut HaRosh, 14):

 

One places the broken piece [of matza] in between the two whole pieces.  He recites the blessing of "hamotzi" on the whole piece and breaks it; then he recites "al akhilat matza" over the broken piece and breaks it, and then he eats from both of them, a kezayit of each one.  One who wishes to fulfill all opinions recites "hamotzi" and "al akhilat matza" and then breaks both of them..."

 

In other words, the Rosh maintains that after reciting "hamotzi" and "al akhilat matza" one should eat an amount of two "kezeitim" - one kezayit-worth from the whole matza, and another kezayit from the broken piece.  This view is codified by the Tur (475) and Shulkhan Arukh (475:1).  What is the reason behind this halakha?  Why must one eat two "kezeitim"?  The Bach answers that all year round one must optimally eat a kezayit of bread after reciting "hamotzi."  Therefore, on Pesach night one must eat twice this amount - one kezayit for the recitation of "hamotzi," and another for the special mitzva of eating matza.  But the Achronim questioned this explanation in light of the fact that we never find any obligation to eat a kezayit after reciting "hamotzi."  In defense of the Bach, the Perisha answers that in fact one is not required to eat a kezayit from the matza upon which he recited "hamotzi," only from the matza upon which he recited "al akhilat matza" (which is the matza through which he fulfills the special mitzva of eating matza on Pesach night).  However, we are in doubt regarding to which of the two matzot the berakha "al akhilat matza" applies - the whole matza or the broken matza.  Therefore, one must eat a kezayit from both pieces. 

 

     This answer also raises considerable difficulty.  Firstly, the overwhelming majority of Rishonim rule conclusively that the berakha "al akhilat matza" refers to the broken piece.  (These Rishonim include Rashi, Tosafot, Rabbenu Chananel, Rambam, Ran, Maharam Chalawa, Rabbenu David, the Chinukh, Ramban, Rashba and Ba'al Hamaor, among others.)  Furthermore, as the Be'ur Halakha asks (475:1), once the berakha is recited on both pieces of matza, then it applies to both; as such, only one kezayit from both pieces of matza should be required.

 

     In any event, the Shulkhan Arukh (475:1) rules in accordance with the view of the Rosh, that one must eat two "kezeitim."  Despite his questioning of this ruling in Be'ur Halakha (as cited), the Mishna Berura concludes that one should preferably follow this view.  He adds, however, that if one ate only one kezayit, he has certainly fulfilled his obligation.  We will return to the practical ramifications of this issue after we first clarify the precise measurement of a kezayit.

 

III. The Measurement of a Kezayit

 

     There are several different aspects to this issue; we will deal with them one at a time:

 

The Relationship Between a "Kezayit" and a "Kebeitza"

 

     An apparent contradiction within the Gemara seems to emerge regarding the size of a kezayit in proportion to a kebeitza.  The Gemara in Yoma (80a) establishes that the human throat cannot swallow more than a single egg of a hen, and the Gemara in Keritut (14a) states that the human throat cannot contain more than two olives.  The implication is, therefore, that a kebeitza - the size of an egg - is twice the size of a kezayit - the size of an olive.  Other Gemarot, however, indicate otherwise.  The Gemara in Eruvin (82b) concludes that the size of two average "meals" amounts to eighteen "gerogerot" - dates.  Now from the mishna there in Eruvin it emerges that two average "meals" contain five and one-third kebeitzim.  Thus, we must conclude that five and one-third kebeitzim contain eighteen dates, and therefore one date equals .296 of an egg, or a little less than a third. 

 

     Herein lies the problem.  The Gemara in Shabbat (91a) records that Rava asked Rav Nachman, "What is the law if one threw an olive-sized piece of teruma into a house that was tamei?" [He replied: "The law in regards] to what? If in regards to Shabbat [a minimum of] the size of a date is required."  The implication here is that a kezayit is smaller than a gerogerot  Thus, if a date is around one-third of an egg, then an olive must be even smaller than that!

 

In other words, whereas this calculation renders a kezayit less than a third of a kebeitza, the inevitable conclusion we reached based on the Gemarot in Yoma and Keritut is that a kezayit equals one-half a kebeitza.

 

The Halakhic Ruling

 

     One view in the Rishonim is that of Rabbenu Tam (Tosafot in Eruvin 80b, Yoma 80a, and Chulin 103b), the Raavya (Pesachim 525), Terumat Hadeshen (1:139), Maharil ("Seder Hahaggada") and other Rishonim.  They maintain that a kezayit is half a kebeitza, and the aforementioned Gemara in Eruvin dealt with a different, smaller type of date (such as one without a pit).

 

     The second opinion is that of the Rambam, who indicates that a kezayit equals around a third of a kebeitza (see Hilkhot Eruvin 1:9), as understood by several Acharonim (Magen Avraham 486:1, Peri Chadash).  To resolve the aforementioned Gemara in Keritut according to this view, the Gera (to Shulchan Arukh O.C. 486) suggests that the Gemara there refers to eggs without the shells, while the Yeshuot Yaakov (O.C. 301) explains simply that the Gemara in Keritut argues on the Gemara in Eruvin.  (Other answers have been offered, as well.  A particularly intriguing view is that of the Rashba [Mishmeret Habayit 96a], who maintains that a kezayit is even smaller - less than a quarter of a kebeitza!)

 

     The Shulchan Arukh (486) states, "The measurement of a 'kezayit' - some say that it equals a half a 'beitza.'"  At first glance, it appears that the Shulchan Arukh rejects the view of the Rambam.  It may be, however, that he actually viewed the Rambam's position - that a kezayit equals less than a third of kebeitza - as the most instinctively obvious opinion, whereas this amount corresponds with the size of olives in his day.  He therefore felt the need to cite the dissenting view, that empirical evidence notwithstanding, a kezayit equals one-half a kebeitza.  (See Rav Chayim Na'eh, "Shi'urin Shel Torah," p. 190, note 24.)

 

     The Mishna Berura (486:1; 190:10; 456:2) rules that regarding Torah obligations one should follow the more stringent view and eat the size of half a kebeitza, while for issues involving rabbinically ordained requirements one may be lenient and use only a third of a beitza.  When an issue of "berakha acharona" is at stake, one should recite a berakha only on the consumption of half a beitza, since we never recite a berakha when its obligation is in doubt.  Likewise, whereas a berakha is recited on the mitzva of marror, one should follow the stringent view despite the fact that its obligation nowadays is rabbinic, unless one is ill and finds it difficult to eat a full half-beitza of marror.

 

     All this regards the proportion of a kezayit to a kebeitza.  We now turn our attention the size of a kebeitza itself.

 

The Measurement of a "Kebeitza"

 

     Two basic questions surround the measurement of a "kebeitza" - whether or not to include the shell in the measurement, and the precise measurement of an average-sized egg with its shell.

 

1)     Whether to Include the Shell in the Measurement of a Kebeitza

 

     The Noda B'Yehuda (kama, O.C. 38) claims that this discussion depends upon the aforementioned dispute regarding the relationship between a kezayit and a kebeitza.  According to the view that a kezayit amounts to half a beitza, a beitza is determined without taking the shell into account.  If, however, a kezayit is only one-third a kebeitza, then the shell must be included when calculating the size of a kebeitza.  Why?  As we saw in the previous section, the position that a kezayit is half a kebeitza is derived from the Gemara's comments regarding the quantity of food that can be contained in the human mouth at one moment.  Clearly, this calculation does not take the shell into account, as it considers one eating an egg.  The dissenting view, by contrast, that views a kezayit as one-third of a kebeitza, emerges from the discussion in Eruvin regarding certain measurements that depend upon the Biblical standard of a "kav."  As we know, a "kav" is determined with eggs still in their shells. 

 

     The Mishna Berura (486:1), however, disagrees, contending that according to all views a kebeitza is determined by the measurement of an egg with its shell.  (The Chazon Ish takes strong issue with the Mishna Berura's ruling in this regard - Kuntras HaShi'urim, O.C. 39:17.  Indeed, many Acharonim - including the Vilna Gaon 486 - seem to understand differently from the Mishna Berura.) 

 

2)     The Measurement of an Average-Sized Egg

 

     The Rambam writes in several places (commentary to Ediyot 1:2 and Keilim 2:2, introduction to commentary to Masekhet Menachot) that he measured as precisely as he could and found that a "revi'it" mentioned throughout the Torah amounts to 26 Arab drams  (silver coins) of wine and 27 drams of water.  Therefore, since a "revi'it" equals a kebeitza and a half, a kebeitza amounts to two-thirds of 27 drams.  Based on this calculation, Rav Chayim Na'eh proceeded to measure a dram at 3.2 grams, and thus concluded that the volume of a kebeitza is 57.6 cubic centimeters.  The problem is that Rav Chayim Na'eh measured according to the Turkish dram of recent times, while the dram was most likely a smaller measurement, 2.83 grams.  (See "Midot V'Shi'urei Torah" 13:7 and 30:6.)  According to this standard, a beitza amounts to 50 cubic centimeters.

 

Are Modern Eggs Smaller?

 

     Generally speaking, the Torah's standards of measurement of length are determined by the length of human body parts ("amma," "tefach," "agudal," "etzba") while volume measurements are determined by the volume of various foods ("se'a," "beitza," "gerogeret," "zayit," etc.).  In certain instances, however, Chazal defined measurements according to the size of a food and a body part.  The measurement of a "revi'it" is such an instance.  It has been defined as both one and one-half beitza, as well as 2x2x2.7 "etzba" (see Pesachim 109a-109b).  Over the course of the generations, however, the poskim have noted the discrepancy between these two measurements.  (One particularly early mention of this problem appears in the Tashbatz, 3:33.)

 

     The first among the Ashkenazic authors to address this issue was the Noda B'Yehuda (in his commentary, "Tzelach" to Pesachim 116).  He writes that we have no choice but to conclude that either people's body parts became larger, or the eggs and fruits of contemporary times are smaller than those of the Talmudic sages.  He concludes, "It is well known that the generations continue to get smaller, and it is [therefore] inconceivable that our thumbs are larger than the thumbs during the times of the Talmudic sages.  We have no choice, then, that the eggs in our times have become smaller."  Based on this analysis, he rules that a kezayit, which equals half a kebeitza, is determined today by an entire modern-sized egg.  He adds that he himself follows this measurement of a kezayit regarding all relevant halakhic issues, such as consumption of matza and marror. 

 

     In other words, in the view of the Noda B'Yehuda, we must double all measurements dependent upon foods.  This position was adopted - albeit with some modification - by the Vilna Gaon (Ma'aseh Rav 105), Rabbi Akiva Eger (Shut Hachadashot 39) and the Chatam Sofer (Shut, O.C. 127 & 181).

 

     Rav Chayim Na'eh composed a work entitled "Shi'urei Torah" in which he seeks to disprove this stringency of the Noda B'Yehuda.  Among his proofs is his calculation according to the dram measurement of the Rambam that concludes that a kebeitza amounts to a modern-sized egg, not more.  He adds that this has been the common practice throughout the generations.

 

     The Chazon Ish, however, wrote a pamphlet called, "Kuntras Hashi'urin" to dispute the view of Rav Chayim Na'eh.  He writes that whereas the measurement is determined by the sages of each generation and a contradiction exists between the two standards, we must assume the larger measurement.  He adds that once the Noda B'Yehuda arrived at this ruling which then became widespread and accepted, it assumes the status of a decree issued by a Bet Din for the entire nation.  However, he continues, these larger measurements may be employed only as a stringency - not as a leniency.  Thus, an ill patient on Yom Kippur, for example, who may eat less than the minimum amount of violation at certain intervals, should follow the smaller - in this case more stringent - measurement.

 

     The Mishna Berura (486:1 and Be'ur Halakha 271:13) addresses the question of whether or not to double the Talmudic measurements, and poses a serious challenge to the position of the Noda B'Yehuda.  As we have seen, the Gemara posits that the human throat can contain a full kebeitza, and the Gemara also comments (Yoma 80) that both cheeks can simultaneously contain more than a revi'it.  If we double the measurements, and a halakhic kebeitza amounts to two of our eggs, then this is realistically impossible!  His challenge notwithstanding, the Mishna Berura rules that one should follow the stringent view of the Noda B'Yehuda regarding mitzvot of Biblical origin, such as the consumption of matza and kiddush Friday night.

 

     In part two of the shiur, we will translate this discussion into practical terms, in an attempt to determine how much matza one must eat at the seder.

 

[Here is a fascinating solution to the 600 year old riddle of 2x2x2.7 etzba vs. 1.5 beitza: If you place your thumb on a ruler, it will indeed measure 2.3~2.5cm in width.  Which corresponds with the measurement Tashbetz, and all those achronim (Noda B'Yehuda, Chatam Sofer and Chazon Ish to name a few) who doubled the shiur of an egg on this basis - a revi'it thus being v.150cc.

 

     However, it was once pointed out to me that artisans of old, when wishing to measure quickly, and without a ruler, would use their thumbs, by placing one next to another and then alternatively lifting the far thumb and place it next to the near one.  Thus "inching" their thumbs along the surface while counting (much like is still done with feet when lacking a tape measure).

 

     Try this at home along a centimeter ruler and you will find that because of the flexibility of the fleshy sides of your thumbs, they become compressed slightly and thus 10 thumbs = 20cm or 1 thumb = 2.0cm.  4x4 x 5.4 = 86.4cc or Rav Chaim Na'eh and the Rambam's calculation based on 1.5 modern eggs!

 

     Another point: The Noda B'Yehuda's assumption that "the generations (of humans) continue to get smaller" MIGHT have been true from the biblical period until the time of the mishna. However, hundreds of sets of Roman armor that have survived until today testify to the fact that if anything we are presently considerably larger than the people in that time.

 

     We must bear in mind, however, the Chazon Ish's point that once the Noda B'Yehuda's view became widespread, it takes on the status of a decree of Beit Din. -Rav Mordechai Friedman, ed.]