(Mishnah): Throughout the seven days, a person makes his Sukah permanent and his home temporary.

If rain begins to fall, when may he leave the Sukah? When the barley soup becomes ruined (which takes place when even a small amount of water falls into it).

The Chachamim made a parable for this, about a slave who comes to pour the cup of his master and the master throws the jug back in his face.

(Gemara): The Pasuk states (Vayikra 23, 42), "You shall "Teishvu" in Sukos" - Teishvu means dwell (as you do in your house).

Just as you say (Devarim 11, 31) "You shall inherit it and dwell (Viyshavtem) in it" - the word Viyshavtem means dwell rather than sit. We learn from here that he should eat, relax and bring his utensils into the Sukah.

The Mishnah had taught: If rain begins to fall, when may he leave the Sukah? When the barley soup becomes ruined...etc.

Even if the barley soup was not ruined but there is enough rainfall to ruin it, he may leave.

Not only if it is a barley soup; if any soup became ruined, he may leave.

Beraisa: Just as he may leave on account of the rain, he may leave on account of hot weather or mosquitoes.

Both Rabban Gamliel and R. Eliezer would enter and leave at any time of the night. (If at any time the rain stopped, they would return to the Sukah, even in the middle of the night.)

One student of R. Mana instructed one of the relatives of the Nasi that if a person left the Sukah (due to rainfall), he need not return during the night if the rain stops; he had not heard that both Rabban Gamliel and R. Eliezer would enter and leave at any time of the night.