No, I haven’t gotten the mah kashe l’Rashi bug out of my system. For this week I want to focus on a Rashi on a Mishna in Sukkah. The Mishna (20b) tells the story of Tevi, the slave of Rabban Gamliel, who slept under a covered bed in the sukkah, which is not an acceptable way of fulfilling the mitzvah. Rabban Gamliel boasted to the other Chachamim of Tevi’s wisdom, as Tevi’s actions demonstrated that he knew that a slave is exempt from yeshivas sukkah.
Rashi d”h ma’aseh explains: slaves are exempt from sukkah because women are exempt from mitzvos aseh she’hazman gerama [my note: the obligation of slaves parallels that of women], and where a women would be chayeves a slave would also be chayav.
If Rashi had explained that a slave is exempt from sukkah because women are exempt and stopped there, mah kashe l’Rashi is a no brainer – the Mishna leaves one wondering why a slave is exempt, and Rashi helpfully provides an answer. But Rashi doesn’t stop there – note the part I bolded. Rashi adds to his explanation that when a women is obligated in a mitzvah a slave is also obligated. Mah kashe l’Rashi that demands this extra line of clarification? The Mishna is not discussion chiyuvim, it is discussing exemptions!
Just to throw one side difficulty into the mix: the gemara (28a-b) explains that women theoretically are obligated in sukkah just like matzah, but there is a halacha l’Moshe m’Sinai which exempts them in this case. So the real reason women are exempt in this case has nothing to do with zman gerama – it is a special halacha l’Moshe m’Sinai! (Ok, so you will argue that the hllm”s is a just a giluy milsa not to compare sukkah to matzah, and m’meila it is a plain old zman gerama, but I still want to note the issue).