The Obligation of the First Night of Sukkot
Although the Torah obligates a seven-day mitzva to experience the sukka, the mitzva is not “quantified” in the manner of other, more concretely defined mitzvot. The gemara (27a) quotes the opinion of R. Eliezer, who specified that the mitzva requires 14 meals over the course of Sukkot. However, the Rabbanan respond that one may schedule his own sukka experience. While all sleep and eating must occur within a sukka, a person is free to determine how often to eat or sleep. The Torah formulated the mitzva with the word “teishvu,” which evokes an experience similar to typical home residence – in the gemara’s phraseology, “Teishvu ke-ein taduru.” Since residential experience is not quantified, or regulated but rather differs from person to person, the sukka experience similarly isn’t a “one-size-fits-all” requirement.
Despite the flexible nature of this mitzva, eating in the sukka the first night of Sukkot is mandatory and regulated. The gemara (27a) cites a gezeira shava between Sukkot and Pesach, each of which occurs on the 15th of their respective months. This textual bridge mandates that a person eat in the sukka on the first night of chag, just as he is obligated to eat matza on the first night of Pesach. What is unclear from the gemara is the nature of this mandate.
Does this textual association establish an autonomous mitzva to eat on the first night? This would mean that while sukka residence remains optional on the first night, as on the rest of the chag, there an independent mitzva to eat on the first night, and since it is Sukkot, any eating must take place in the sukka. Alternatively, the gezeira shaveh may solidify and bolster the mitzva of sukka residence on the first night. During the rest of Sukkot, sukka residence is optional; on the first night, in contrast, the mitzva to reside in the sukka is obligatory. According to this view, the mitzva on the first night is not an extrinsic mitzva that incidentally has to be executed in a sukka. Rather, the mitzva of sukka residence is rigid on the first night, as opposed to its flexible nature the rest of the week. This question leads to several interesting nafka minot.
Tosafot (27a) cite a Yerushalmi that questions whether the obligation on the first night can be fulfilled by eating any food or only grain-based foods. Presumably, if the first night obligation is inherently sukka-based, even non-grain foods should suffice, as these foods typically require a sukka. However, if the mitzva is independent, perhaps bread-based foods should be necessary, just as they are required to satisfy the akhila requirement on the first night of Pesach.
The Yerushalmi raises a second issue that seems to indicate that the first night obligation is an autonomous, non-sukka related obligation. Perhaps, the Yerushalmi reasons, a person shouldn’t eat in the afternoon prior to Sukkot, in order to augment his appetite for the first night eating. Avoiding food to ensure appetite is not inherent to the sukka experience. If this rule applies the first night, it is clearly an “import” from the definition of akhilat matza on Pesach. The Torah described eating matza as a “showcase” for halakhic acts of eating mitzva articles. The gezeira shaveh exports this obligation from Pesach to Sukkot.
These two discussions in the Yerushalmi highlight the question as to whether the mandatory eating in the Sukka on the first night is a stricter application of the general sukka schedule or represents an autonomous mitzva to eat, which incidentally must be conducted in the sukka.
The Ritva appears to address this issue from the standpoint of the “shiur,” or the quantity of food that one is obligated to eat the first night. Typically, the mitzva of eating in a sukka is accomplished through the ingestion of at least a ke-beitza’s worth of food (roughly the size or a large egg). This quantity constitutes a “substantial” eating experience, rather than a light snack. If the mandatory eating on the first night is a reinforcement of the week-long sukka mitzva, this shiur of ke-beitza food should be eaten. This is, in fact, the Ritva’s initial suggestion. Subsequently, however, he reverses his opinion and suggests that a ke-zayit worth of food would suffice. A ke-zayit governs the typical, generic act of eating and is required on Pesach night. Presumably, if the mitzva to eat on the first night is an external mitzva, a ke-zayit would suffice. In fact, the Rambam (Hilkhot Shofar Sukka ve-lulav 6:7) also quantifies the mitzva to eat with the ke-zayit shiur, implying that he also viewed the mitzva as external.
Perhaps the most telling indicator that the first-night mitzva is intrinsic is a minority shita cited by the Ritva in the name of an anonymous French Rabbi who claimed that the obligation on the first night includes sleeping, not just eating. Clearly, this reflects a reinforcement of the generally voluntary teishvu ke-ein taduru obligation. During most of Sukkot, this mitzva dictates that IF a person eats or sleeps, he should do so in the sukka. On the first night, however, we are mandated to sleep and eat in the sukka. If the first night were a “foreign import” - an autonomous mitzva to eat imposed through the gezeira shaveh - the mitzva would be limited to eating. The only way to extend the mitzva to sleeping is to cast it as an internal sukka mitzva.
Finally, if the mitzva is indeed an external act of eating legislated by the model of Pesach, perhaps it would obligate sukka eating even under conditions which are typically exempt. Tosafot in Berakhot (49) assert that eating must be conducted the first night even under inclement weather conditions, which typically exempt one from eating in the sukka. The exemption of mitzta’er does not apply on the first night. Interestingly, the Rema (679) cites this opinion, but the Shulchan Arukh does not (The Shulchan Arukh resided in Tzefat, which typically didn’t experience inclement weather on Pesach, whereas the Rema lived in Poland, which typically did. His pesak was not theoretical; it demanded great commitment to this first night mitzva.)
Clearly, the mandate to eat under conditions that normally exempt the mitzva indicates a purely external mitzva that is unrelated to the general mitzva and patterns of the seven-day sukka mitzva. Mitzta’er or suffering typically exempts from the seven-day Sukka mitzva. A mandate to eat under these conditions would more likely be based upon an autonomous mitzva of eating on the night of the 15th.