Yesterday, we noted the Gemara’s brief discussion in Masekhet Rosh Hashanah (28b) regarding the case of one who decides he wants to sleep in the sukka after the end of Sukkot. The Gemara posits that seemingly, if we accept the view that a mitzva act is valid even if it is done without any intention to fulfill the mitzva, sleeping in the sukka after Sukkot would violate bal tosif – the prohibition against adding onto the Torah’s laws. Even though the individual sleeps there for enjoyment, and not for the mitzva, nevertheless, according to this view, intention is immaterial, and thus he performs a bona fide mitzva act when it is unwarranted, in violation of bal tosif. The Gemara then dismisses this argument, asserting that bal tosif forbids adding onto mitzvot at the time they are to be observed, but not performing a mitzva act when the mitzva does not apply.
As we saw, this Gemara appears to disprove the view taken by Rav Yaakov Ettlinger, in his Bikurei Yaakov (625), that one does not fulfill the mitzva of sukka without intending to commemorate the “clouds of glory” that encircled Benei Yisrael in the wilderness. Several Acharonim posited that irrespective of the general question as to whether one can fulfill mitzvot without intention, one must have in mind when living in the sukka to commemorate our ancestors’ miraculous existence in the desert. Rav Ettlinger suggested that this requirement may apply even on the level of be-di’avad – meaning, that one who fails to have this intention has not fulfilled the mitzva. This position, however, seems to be negated by the Gemara’s discussion, as the Gemara presumes that sleeping in the sukka purely for comfort and enjoyment could constitute a valid mitzva act that could therefore violate bal tosif when the act is not required.
Rav Ettlinger himself addresses this question, in the Tosefet Bikkurim appendix to Bikurei Yaakov, and he answers by proposing a novel reading of the Gemara’s discussion. He notes that the Gemara never actually entertained the possibility that it would be forbidden to sleep in the sukka after Sukkot. The Gemara made its point as an objection to the view that mitzva performance does not require intention, asking that according to this view, “One who sleeps in the sukka on the eighth day” – meaning, the day after Sukkot – “should receive lashes” for transgressing bal tosif. As this is clearly not the case, the Gemara argues, we may perhaps prove that intention is necessary for the satisfactory performance of a mitzva act. Why, Rav Ettlinger asks, did the Gemara assume from the outset that one is permitted to continue living in the sukka on the eighth day?
Rav Ettlinger answers by suggesting that the Gemara refers to the practice in the Diaspora to reside in the sukka on Shemini Atzeret (albeit without reciting a berakha). This practice is established elsewhere in the Gemara (Sukka 47a), and is based on the fact that Diaspora communities observe two days of Yom Tov to commemorate the time when remote communities were unsure of the date. Just as Diaspora Jews observe a second day of Yom Tov, they similarly remain in the sukka on Shemini Atzeret, because in ancient times Diaspora communities were unsure whether that day was Shemini Atzeret or the seventh day of Sukkot. The Gemara raised the question of how we can justify this practice according to the view that a mitzva act is valid without intent. Since we know with certainty that this day is Shemini Atzeret, sleeping in the sukka would, seemingly, transgress bal tosif according to the view that intention is not required to fulfill a mitzva. (According to the view that intention is required, this practice does not violate bal tosif, as one enters the sukka to fulfill the mitzva only commemoratively, and not with the intention of fulfilling the actual Torah command.) As such, the Gemara speaks not of one who sleeps for enjoyment in the sukka on Shemini Atzeret, but rather of a Diaspora Jew who sleeps in the sukka on Shemini Atzeret as required by Halakha. Therefore, since he sleeps for the sake of the halakhic requirement, he presumably does so with the intention of recalling Benei Yisrael’s miraculous conditions in the wilderness, and for this reason the Gemara questioned why this does not constitute a violation of bal tosif.