On today’s daf, the mishnah teaches:
Those on the path to perform a mitzvah are exempt from the mitzvah of sukkah.
This is actually a general talmudic precept: If you’re already performing a mitzvah, you are exempt from doing another one until you are finished. The Gemara goes on to inquire about the biblical prooftext for this precept, which many of us will find familiar as it is found in the Shema: Impress (words of Torah) upon your children. Recite them when you stay at home and when you walk upon the way, when you lie down and when you rise up. (Deuteronomy 6:7)
The Gemara then asks:
The verse does not specify the way along which one is walking. Are we not dealing with one who is walking along the way for a matter of a mitzvah, and nevertheless, the Merciful One says to recite Shema? Apparently, one is obligated to do so even if he set out to perform a mitzvah.
The Talmud raises a logical challenge. We learn in the Shema that we are commanded to do two things at the same time: teach one’s children Torah while walking with them. How can we then say this verse leads to the opposite conclusion — namely, that we are exempt from doing a second mitzvah while engaged in the first?
The Gemara answers:
What is the meaning of: “When you sit…and when you walk”? It comes to underscore: It is in your walking, undertaken for personal reasons and of one’s own volition, that you are obligated to recite Shema; in walking with the objective of performing a mitzvah, you are exempt from reciting Shema.
The Gemara here makes clear that the verse is referring to discretionary tasks, which do not exempt one from performing a mitzvah, not to obligatory ones — i.e. those undertaken in the performance of a mitzvah — during which one is exempted from performing a second mitzvah. If you are walking to perform a mitzvah, you are in fact exempt from reciting the Shema. Only if you’re walking for your own purposes are you obligated.
The Gemara cites various examples of this precept. A groom is not required to say the Shema on his wedding night when he is presumably preoccupied with the upcoming mitzvah of procreation with his new bride. During the week of celebration following the wedding, neither the groom nor his attendants are required to pray or to put on tefillin. And more germane to the subject at hand is where the mishnah started: If you are on your way to do a mitzvah, you are not obligated in the mitzvah of sukkah.
This makes sense if there is a journey involved and there is no sukkah to be found. But what if there is? Why would one then be exempt?
The rabbis of the Talmud may have once again been ahead of their time in establishing this rule.
Recent research about multitasking and its effect on brain health shows that rather than increasing productivity, trying to do two things or more at once can actually decrease effectiveness by up to 40%. That’s because goal shifting (changing from one task to another) and role activation (changing the set of rules from the previous task to the next) require attention. If you try to do two things at once, it’s likely you’re not able to truly attend to either.
The rabbis apply this thinking to the fulfillment of mitzvot, positing that one of the reasons for this rule is that you may be unable to muster the proper intention for performing a mitzvah if you are in the midst of performing a different one. So the next time you have an opportunity to do two mitzvot, rejoice! And then do them one at a time.
Read all of Sukkah 25 on Sefaria.