Today's daf is dedicated by Sara Berelowitz "in memory of my beautiful Mom Kayla bat Yehuda on her 8th yahrzeit who we all miss very much." And by Aviva Adler for a refuah shleima for Leah bat Chaya Rivka. And in memory of Yaakov Israel ben Chaim Peretz, Rav Yaakov Kanievsky, the Steipler. Those who write and sell sifrei Torah, tefillin, and mezuzot are exempt from shema, davening and tefillin as one involved in a mitzva is exempt from other mitzvot. Those traveling or on their way to do a mitzva or guards and others, in what situations are they exempt from sitting/sleeping in a sukkah? What type of sick person is exempt from sukkah? Rava held that one who is very uncomfortable sitting in a sukkah is exempt. What amount is considered a "snack" which one would not need to eat in a sukkah? What about a nap? What is the law regarding sleeping/napping with tefillin? How does this compare to the laws of sukkah? Rav held that one should not nap in general, however, he permitted a short nap - how short? The mishna brings a few cases where rabbis ate small amounts and either insisted on eating in the sukkah or didn't. The gemara explains their positions.