Reference for Pesachim 10:8
וְאֵין מַפְטִירִין אַחַר הַפֶּסַח אֲפִיקוֹמָן. יָשְׁנוּ מִקְצָתָן, יֹאכְלוּ. כֻּלָּן, לֹא יֹאכֵלוּ. רַבִּי יוֹסֵי אוֹמֵר, נִתְנַמְנְמוּ, יֹאכְלוּ. נִרְדְּמוּ, לֹא יֹאכֵלוּ:
Ve'en maftirin after the Pesach afikoman. [I have heard this ("maftirin") explained as in (Psalms 22:8): "Yaftiru besafa" ("They open and say"). My rabbis understood it in the sense of "haniftar mechavero" (taking leave of one's friend), i.e., when one "takes leave" of the meal, it should not be concluded by saying "Afikoman" (acronymic for) "Afiku manaichu" ("Take out your utensils"), i.e., "Take your utensils from here and let us go and eat elsewhere." One may not do this in order to eat loaf (i.e., matzah) or anything else — a decree lest one come to eat of the Pesach in two places. But to eat other things in one's original place is permitted, so long as he does not leave his company to eat them with a different company. And there is a view in the gemara according to which "afikoman" is understood as "Afiku minei metika" ("Bring out kinds of sweets"). After eating the Pesach they are not to "take leave" of the meal by partaking of sweets and fruits, which they were wont to eat as dessert. (They are not permitted to do so) even in their place, so that the taste of the Pesach not leave their mouths. This is the essential interpretation. And just as "ein maftirin after the Pesach afikoman," so "ein maftirin after matzah afikoman." That is, when there is no Pesach, one must eat an olive-size of matzah at the end. And after that matzah, one may not take leave of it with the eating of something else.] If some of them slept, they may resume eating; if all of them slept, they may not resume eating. [If they began eating their Pesach, and all of them fell asleep, they may not resume eating (when they awake), the impression thereby being given of eating in two places. For their sleeping interrupts their intent to continue eating, so that it (eating when they awake) is like eating in two places. This is just a stringency (of observance and not the essential halachah). The same holds for matzah at this time.] R. Yossi says: If they slumbered, they may eat; if they fell asleep, they may not eat. [This refers to the first tanna's statement: "If some of them slept, they may resume eating." R. Yossi comes to tell us that this is so only if they slumbered but did not actually fall asleep. But if some of them fell asleep, they (those who fell asleep) may not resume eating when they awake. The halachah is in accordance with R. Yossi.]