פירוש על סוכה 2:4

והאילנות דפנות לה כשירה – and this is the case where the trees are thick and strong and don’t move when a frequent wind comes. And it is also necessary to fill between the branches with straw and stubble so that wind will not move them, and all partitions that cannot stand with frequent wind is not a partition.

Introduction The first section of this mishnah continues to discuss walls used as trees for the sukkah. The second section begins to discuss a new topic: when a person is obligated to be in the sukkah and what a person is obligated to do there. This will be the topic of the remainder of the chapter of the mishnah. Up until now all of the discussions have been about the structure of the sukkah itself.

שלוחי מצוה פטורים – for someone who engages with [the performance of] a commandment/Mitzvah is exempt from the Commandment, and not only are they exempt at the time that they are engaged with [another] Mitzvah, but even at a time when they are not engaged in it, for example, a person who goes to receive and welcome his teacher or to redeem captives is exempt, even at the time of his resting.

If one makes his sukkah between trees, so that the trees form its walls, it is valid. In this case a person uses a tree for all of the sukkah’s walls, not as support for the walls but rather as the walls themselves. This might easily happen if there were some bushy trees that could block him on at least three sides. He supports the skhakh with poles and not with the trees. The sukkah is valid and he may even use it on the festival, since the sukkah is not actually resting on the trees.

חולין ומשמשיהן פטורים – and even those who are simply sick, and he who permits to annual a positive commandment of the Torah because of a mere illness, and is pained because of bad smell or because of bed-bugs and fleas where he is exempt, and similarly, those who walk on the path and those who guard the gardens and orchards, the Rabbis exempted them from the Sukkah, the reason is because it is written (Leviticus 23:42): “You shall live/dwell in booths [seven days; all the citizens of Israel shall live in booths],” like the way you live, and wherever there is a thing that because of that, he would leave from his dwelling, he can also leave from his Sukkah. But one who makes his Sukkah from the outset in a place that is appropriate to be in pain while eating or sleeping, such as in a place where he is afraid of robbers while sleeping, but he is not afraid of thieves or robbers while eating, even regarding eating, he does not fulfill his obligation in that Sukkah, for since it is not appropriate to do within it all of his needs of eating and drinking and sleeping, for we require where he can reside, and this is a case where it is not like “living/residing.”

Those who are agents to perform a mitzvah are exempt from [the obligations of] sukkah. People who are busy performing a mitzvah and find it difficult to eat or sleep in a sukkah are exempt from the sukkah. This is due to the general rule that one who is engaged in one mitzvah is exempt from performing another mitzvah. However, this is only true if by eating or sleeping in the sukkah he would be unable or distracted from performing the other mitzvah he set out to perform. If he could perform both at the same time, then he must do so.

אוכלים ושותים עראי – a small amount to remove his hunger, and his intention is to eat a meal afterwards.

People who are sick and their attendants are exempt from [the obligations of] sukkah. People who are sick enough so that being in the sukkah would be a discomfort for them, are not obligated for the laws of the sukkah. Being in the sukkah is not supposed to be painful and therefore, one who would be pained by being in the sukkah is exempt. Note, that the mishnah is not addressed to those who might “fake” being sick in order to get out of sleeping or eating in the sukkah. It is addressed to those who are so zealous about keeping the commandments that they would risk injury or at least illness to do so. The rabbis tell such a person to get out of the sukkah the sukkah is not supposed to cause one pain.

One may eat and drink casually outside the sukkah. Meals must be eaten in the sukkah. However, snacking may be done outside of the sukkah. According to the Rambam, while one can snack outside of the sukkah, one who strives to only eat and drink in the sukkah is praiseworthy.