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Osek Ba-Mitzva Patur Min Ha-Mitzva (I)

Rav Moshe Taragin
In memory of Rabbi Aaron M. Wise and Fred Stone z"l.
Text file


Several gemarot assert the well-known principle of “osek ba-mitzva patur min ha-mitzva” –that involvement in a prior mitzva excuses a person from performing a second mitzva which he may encounter. The gemara (Sukka 25a) derives this from a pasuk in shema which frames mitzva performance as "be-shivtekha be-veitekha," “when you are sitting in your home” – in your daily residence/routine. This implies that when a person is previously committed to religious tasks (prior mitzva involvement), he is exempt from subsequent mitzva obligation.


This halakha triggered a well-known debate between Tosafot and the Ran as to the scope of this exemption. Tosafot limited the exclusion to situations in which the two contending mitzvot cannot be performed simultaneously – "i efshar le-kayem shneihem." Only in these scenarios would the osek principle exempt one from mitzva performance. A broader exclusion would theoretically exempt mitzva performance even if a person were simply wearing a tallit and tefillin, since technically he is fulfilling a mitzva. This would lead to the unthinkable prospect of exempting those who wear tefilin or tallit all day from ANY AND EVERY mitzva! Since this is absurd, Tosafot limit the exemption to situations in which the two mitzvot cannot be jointly executed; a tallit and tefillin wearer can certainly multitask additional mitzvot and is therefore obligated to do so.


The Ran in Sukka disagrees with Tosafot and broadly extends the exemption to include cases in which the mitzvot CAN be jointly attended to. This more ambitious position was already developed by the Or Zarua in his comments to Sukka (siman 299). The Or Zarua focuses on the fact that an actual pasuk instructs of this exemption; the SOURCE of this halakha inevitably demonstrates its BROAD application. Exempting a person involved in a mitzva from a second mitzva that would compromise the first mitzva is so obvious that it would not require a pasuk. Why should mitzva "a" be discarded for mitzva "b"? The pasuk is obviously necessary to stretch the exemption to the less obvious scenario – even if the second mitzva can be performed along with the first one, the person is exempt since he is already committed to a religious activity.


Classically, this debate about the SCOPE of the exemption is viewed as a gloss about the NATURE of the exemption. There are two logics suggested for cases in which halakhot are suspended. One model – the model of “dechuya,” contends that the halakha or prohibition still applies, but it is overridden by the more significant halakha or mitzva. For example, if a mitzva can only be performed by violating an aveira, the principle of “asei docheh lo ta’asei” obtains and permits the infraction for the larger good of the mitzva. This prohibition still applies, but the issur is overridden by the compulsion of the “greater” valued mitzvat asei.


Alternatively, a second model exists, typically referred to as “hutra” – a situation in which the prohibition is completely suspended and inactive. For example, if the eighth day after a baby is born falls on Shabbat, mila can be performed, even though circumcision would usually violate Shabbat. In this instance (based on a pasuk), Shabbat prohibitions relating to mila SIMPLY DO NOT apply. Shabbat proscribes certain malakhot as long as they are not vital to mila.


These two models were discussed by the Tannaim in various contexts of “suspended’ issurim, and the aforementioned terms were employed in that discussion. The most famous debate in this regard relates to a situation in which the entire population is tamei and yet a korban was sacrificed (see Pesachim 77a).


Presumably, Tosafot and the Or Zarua are adopting different models to explain the osek ba-mitzva exemption. Tosafot maintained that the second mitzva is OVERIDDEN by commitment to the first mitzva. The second mitzva APPLIES, but it cannot justify abandonment of the first; the interest in successfully expediting the first mitzva overrides the obligation. This override, however, only applies in a situation of conflict, in which the mitzvot are mutually exclusive and one must be ignored to favor completion of the other. Alternatively, the Or Zarua believes that mitzvot are NOT INCUMBENT upon someone who is already occupied with a mitzva. In fact, the SIMPLE READING of the derasha suggests as much. Mitzvot only apply to people who are involved in personal pursuits (figuratively, “at home”); once a person is engaged in religious duty, the mitzva does not apply at all. According to the Or Zarua, osek ba-mitzva is a situation of hutra, and therefore applies even if the two can be jointly performed.


An interesting consequence of this issue would be the question of tashlumim. Most mitzvot cannot be “compensated;” once their period has elapsed, the mitzva is lost. Tefilla is unique in allowing “makeup” performance. If a tefilla was omitted, it can, in many scenarios, be recited during the next tefilla period. If someone was exempt from tefilla because of osek ba-mitzva, should that tefilla be “made-up” during the next tefilla slot? Presumably, if the second mitzva is obligated and osek merely indicates that it should not be performed, tashlumin would be mandated. However, if the second mitzva does not even apply, no tashlumim would be necessary or even meaningful. Thus, Tosafot would embrace tashlumim, whereas the Ran and Or Zarua would not. In fact, the Shulchan Arukh and Taz (Yoreh De'ah 341) discuss the notion of tashlumim for a tefilla that was omitted because of osek ba-mitzva.


R. Soloveitchik developed this makhloket further by applying a second logical determinant to the respective positions. Beyond merely assessing the MECHANICS of the exemption (hutra or dechuya), R. Soloveitchik questioned which ASPECT of the first mitzva defines someone as “osek” and thereby exempt from a second mitzva. Is the fact that a person is FULFILLING a mitzva sufficient to exempt from further mitzva duty, or must he be actively INVOLVED in the performance? Theoretically, Tosafot might claim that a “kiyum” mitzva is sufficient to exempt further mitzvot. Fulfilling a prior mitzva would override future mitzvot that compete with or threaten the original kiyum (i efshar le-kayem shneihem). However, the Ran's version of someone involved in a prior mitzva being completely relieved of any further commands may only apply to someone ACTIVELY involved in the execution of a ma’aseh mitzva. That type of person is not leisurely engaged in a personal routine (be-shivtekha be-veitekha), but rather ACTIVELY engaged in religious duty. Mitzvot for such a person are not incumbent since his physical activity engages him in a routine that is not personal but religious. Thus, Tosafot and the Ran are not merely arguing about the mechanics of the exemption, but are also the different aspects of the original mitzva that displace the second mitzva.


The Rav claimed that this difference was already latent within Tosafot's concern about the tefillin wearer and the Ran's lack of concern. Tosafot believed that any kiyum of a mitzva should, in theory, exempt further mitzvot based on “osek.” Accordingly, a person wearing tefillin all day is constantly involved in the kiyum ha-mitzva and is a candidate for the osek exemption all day long. Since this scenario is absurd, Tosafot limited the “osek” exemption only to situations of mutual exclusivity, "i efshar le-kayem shteihem."


The Ran was unconcerned with this predicament because he believed that only an ACTIVE ma’aseh mitzva would define someone as osek and therefore exempt. Although wearing tefilin all day is an enduring kiyum, it is not an ACTIVE ma’aseh and therefore would not exempt based on osek. Only the ACT of donning tefillin or tzizit would exempt, and this act expires after mere minutes. Thus, no absurd scenario of daylong mitzva exemption emerges.


The ensuing shiur will explore further instances of osek which may indicate whether the kiyum mitzva or the ma’aseh mitzva exempts future mitzvot.

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