The reason given for the mitzva of dwelling in the sukka is “so that your generations will know that I had the children of Israel live in booths, when I took them out of the land of Egypt” (Leviticus 23:43).

According to a tradition recorded by the Sages, this verse is referring to supernatural “clouds of glory” that surrounded the Israelites from the moment they left Egypt until their arrival in the Land of Israel. These clouds shielded them from all the dangers of the perilous journey.

The mitzva of dwelling in the sukka is obligatory for every male aged thirteen and up. Furthermore, in the case of boys who have reached an age at which they can be trained to perform mitzvot, which is five or six years old (and in some cases even earlier), the father must accustom them to observing the mitzva of sukka.

People who are ill are exempt from the obligation of dwelling in the sukka, and the same applies to any person who suffers from a certain level of discomfort in the sukka, as will be explained below.

Women are exempt from the mitzva of sukka, in accordance with the general principle that women are exempt from time-bound, positive mitzvot.

The main activities one must perform in the sukka are eating and sleeping. Some are stringent not to eat or drink anything at all outside the sukka for the duration of the festival. This is a praiseworthy practice if one can adhere to it, but the halakhic requirement is that one is obligated to eat only fixed meals in the sukka. A “fixed meal” is defined as eating bread or a baked item on which one recites the blessing of mezonot (“…who creates various kinds of nourishment”; see the laws of blessings, p. 515). Even these foods are only considered a fixed meal if one eats at least the volume of an egg (about 86.4 cc). Even a smaller amount should be eaten in the sukka if one sits down to eat it in a fixed setting, e.g., with a cup of coffee or after reciting Kiddush.

In cases in which it is obligatory to eat in the sukka, one should recite the following blessing before eating:

“Blessed are You, Lord our God, King of the universe, who sanctified us through His commandments, and commanded us to reside in the sukka.”

After one has left the sukka for an extended period of time and then returns to it, he must recite this blessing again if he wants to eat something that must be eaten in the sukka.

If a person does not eat bread or other foods made of grains during Sukkot, as, for example, one who has celiac and may not eat grain products because of the gluten they contain, he must nevertheless recite the blessing when he enters the sukka for an extended period of time. Similarly, he should recite the blessing if he enters the sukka to eat a full meal, even if does not contain any grain products.

The obligation to sleep in the sukka is more stringent than the obligation to eat in the sukka in that it includes even a brief nap, and even if one is not lying down. This applies throughout the seven days of the festival. Nevertheless, in certain cases detailed below, one is exempt from sleeping in the sukka for reasons of discomfort. In addition, the custom of Lubavitch Hasidim and some other hasidic sects is not to sleep in the sukka at all, for various reasons.

Further reading: For more information on the festival of Sukkot, see A Concise Guide to the Torah, pp. 318, 472; A Concise Guide to the Sages, p. 290; A Concise Guide to Mahshava, p. 72.

In situations in which being in the sukka would entail suffering or discomfort of some kind, e.g., due to a bad smell, rain, insects, or because it is too hot or too cold, there is no obligation to eat or sleep in the sukka. The reason for this is that the mitzva of sukka entails living in the sukka as one lives in his regular home. Consequently, if one would leave one’s home under these circumstances in order to eat or sleep, one may leave the sukka as well. The halakha is different with regard to the first night of the festival, however, as detailed below.

One should avoid erecting a sukka in a manner that will cause discomfort to those using it. If necessary, one should bring fans into the sukka to aid with the heat, or a heater (taking care to follow safety precautions) to aid with the cold.

If one has to leave the sukka in the middle of a meal due to discomfort, or if he began a meal or went to sleep in the house because of discomfort in the sukka, even if the cause of the discomfort has passed, he need not return to the sukka to complete his meal or to continue the night’s sleep. This permission to sleep outside the sukka extends until one wakes from his sleep or until daylight, whichever of the two is later.

Some halakhic authorities exempt a married man from sleeping in the sukka, if the conditions of the sukka do not allow him and his wife to sleep there in the privacy and comfort to which they are accustomed the rest of the year.

On the first night of Sukkot, there is a special obligation to eat in the sukka. The minimum requirement on this night is to recite Kiddush and eat at least the minimal volume of an olive-bulk (about 27 cc) of bread in the sukka. This is in contrast to the rest of the festival, during which one may avoid eating in the sukka completely by limiting himself to eating foods that do not have to be eaten in the sukka.

Likewise, on the first night of the festival, the obligation to eat in the sukka applies even if sitting there causes one suffering, e.g., if it is raining. In such a case, one should wait a while to see if the rain stops. If the rain shows no signs of letting up, one must begin the meal in the sukka anyway, by reciting Kiddush and eating an olive-bulk of bread. After this he may go back inside and continue the meal there.

In localities where there is frequent rainfall in the season of Sukkot, one may place thick sukka roofing [sekhakh] on the sukka so that it will take a longer time for the rain to penetrate. Additionally, one can cover the sukka with a sheet of plastic in advance and remove it just before entering the sukka to recite Kiddush. If one does use such a covering, he must be careful to remember to remove it every time he goes to eat in the sukka.

Ideally, one should not undertake many trips during the intermediate festival days [Hol HaMoed] of Sukkot, so that one can maximize dwelling in the sukka. Nevertheless, since during the year it is customary from time to time to leave one’s house and eat on the road, on Sukkot as well it is permitted to go on a trip even if one is not entirely sure that he will find a sukka on the way. If a person on the road is unable to find a sukka, he is permitted to eat without a sukka. At night he must make a special effort to find a sukka to sleep in, as even during the year one would try his utmost to find proper lodging for the night. If he could not find a sukka, he may sleep outside the sukka.

If one goes on a trip on Hol HaMoed Sukkot and intends to be away for several days in a row, he should make arrangements ahead of time to ensure that he will have a sukka in which he can eat and sleep. Nowadays it is relatively easy to obtain mobile sukkot that can be towed along, or which can be assembled in field conditions.

Further reading: For more information on the idea that dwelling in the sukka is like a taste of the Garden of Eden, see A Concise Guide to Mahshava, p. 76.