Pesachim 10:7-8

Pesachim 10:7

The third cup of wine is poured and they bentch (i.e., recite the grace after meals). Hallel is completed over the fourth cup, and he recites “the blessing of the song” (birkas hashir) over it. (There is a difference of opinion as to what, specifically, is meant by this.) If one wishes, he may drink between the first two cups and the last two cups but one may not drink between the third and the fourth cups.

Pesachim 10:8

One may not eat dessert (afikoman) after the Pesach offering. If some members of the group slept, they may still eat the Passover offering (because, as a group, their attention was still on it) but if all of them slept, they may not eat it (because their attention left it). Rabbi Yosi says that if they lightly dozed, they may eat but if they fell into a deep sleep, they may not eat.