Gemara

Question: What is considered Misnamnem (dozing)?

Answer (Rav Ashi): He is half asleep, and half awake. If one calls to him, he responds, but he cannot give an answer that requires reasoning. When one reminds him (what he heard), he remembers.

Ta'anis 12a (Beraisa - Rebbi): One may eat (before a daytime fast) until dawn;

R. Elazar says, he may eat until Kros ha'Gever (the call of the rooster, or a man who would wake Kohanim in the Mikdash to rise for Avodah).

Version #1 (Abaye): This (Heter to eat again) is only if he did not finish (his meal). If he finished, he may not eat again.

Question (Rava - Beraisa): If he finished and arose, he may eat again.

Answer: That is when he did not remove (the table).

Version #2 (Rava): This is only if he did not sleep. If he slept, he may not eat again.

Question (Abaye - Beraisa): If he slept and arose, he may eat again.

Answer: That is when he was dozing.

(Rav Ashi): Dozing is half asleep...

Pesachim 120a (Mishnah): If some of the group (eating Korban Pesach) slept, they may resume to eat;

R. Yosi says, if they dozed, they may eat. If they slept, they may not eat.

Rabah dozed. Abaye mentioned this.

Rabah: The Mishnah says that if they dozed, they may eat. I only dozed.

Rishonim

Rif and Rosh (Ta'anis 3b and 1:14): The Halachah follows Rebbi.

Rif: The Gemara did not give an explicit ruling (like Version #1 or Version #2). However, since the Gemara toiled to explain dozing, this shows that the Halachah follows Version #2. Also, we are lenient about an Isur mid'Rabanan. Whether or not he finished his meal, if he did not sleep, he may eat until dawn.

Ran (DH Ika): Version #1 connotes that it depends only on finishing. If he did not finish, even if he slept, he may eat. If he finished, even if he did not sleep, he may not eat. Version #2 connotes that it depends only on sleep. If he did not sleep, even if he finished, he may eat. If he slept, even if he did not finish, he may not eat. Therefore, to answer the Beraisa of one who slept and rose, we needed to say that he only dozed. We could not answer that he did not finish. The Rif says that we are lenient like Version #2. I explain that each version has its leniency and stringency! It seems that he holds that Version #2 forbids only if he finished and slept. We could have answered that he did not finish, but that is obvious. (The Beraisa would not have needed to teach it.) Surely it depends on his intent! The Yerushalmi says that if he stipulated, even if he finished and slept, he may eat. Since it depends on his intent, surely sleep during the meal is not a Hefsek. Therefore, we needed to say that he dozed.

Rambam (Hilchos Ta'aniyos 1:8): Any fast for which one may eat the night before, he may eat and drink until dawn, if he did not sleep. If he slept, he may not eat again.

Magid Mishneh: The Rif rules like Version #2. As long as he did not sleep, even if he finished his meal, he may eat until dawn. It depends only on sleep. The Rambam holds like this. It is primary, even though some Ge'onim disagree. The Ra'avad brings from the Yerushalmi that a stipulation helps even if he slept. The (Rif's) Halachos did not bring this. One should be stringent.

Rosh (Ta'anis 1:14, citing the Ra'avad): If he slept, even during the meal, he may not eat again, for it is as if he finished his meal and removed the table, for he diverted his mind from eating. He needs a Berachah (Acharonah) retroactively on what he ate, and a Berachah (Rishonah) on what he wants to eat now. Rabah dozed, and Abaye mentioned this. He thought that he must cease eating, for this is like eating Korban Pesach in two places. We are stringent like Version #2 (in Ta'anis). Even if he slept during the meal before finishing, he may not eat again.

Rosh: The Ra'avad is a big stringency. The Beraisa does not connote like he explains. It says 'until when may one eat and drink'. This connotes that it discusses a Stam person eating at the beginning of the night. Rava teaches that he may eat until sleeping after the first time he ate. Version #1 connotes that after finishing his first meal he may not eat again, but Version #2 connotes unlike this. Also, 'he slept and got up' connotes that he slept on a bed. If he slept at the table, why does it say 'he rose? Also, why does he rule stringently regarding a mid'Rabanan law? Perhaps he does not consider this mid'Rabanan, for the Torah obligates fulfilling his vow. The Ra'avad says that sleep is an interruption that obligates blessing retroactively and for what he will eat. I disagree. Sleeping Arai (haphazardly) during a meal is not Hesech ha'Da'as (diverting his mind). This is unlike the Tosefta (Berachos 4:20) of a Ba'al ha'Bayis who was eating, and a friend called to speak to him. He needs to bless retroactively only if he delayed. There, he interrupted through speaking, and there is Hesech ha'Da'as. Sleeping Arai due to Ones is not Hesech ha'Da'as. We hold like Rav Chisda (Pesachim 101b), that (one who interrupted) need not bless retroactively or for what he will eat, if he ate things for which one must bless where he ate them, since he will return to where he ate. This is even if he went to greet a Chasan and Kalah, and all the more so if for sleep b'Ones, for he stayed where he was fixed (to eat). Pesachim 120 does not discuss interrupting a meal. Rather, it is like the Rashbam explains. Rabah dozed after he began eating Matzah, which is in place of Korban Pesach. Everyone holds that sleep during a meal is not a Hefsek.

Rosh: The Rif is lenient, like Version #2. This is unlike the Ra'avad. R. Chananel brought the Yerushalmi, which says that one who rose after sleeping is forbidden only if he did not stipulate, but if he stipulated, he is permitted.

Rosh (Teshuvah 27:7): Based on the Bavli, one who goes to sleep stipulates that he may drink the entire night. Even though the Yerushalmi connotes that a Tanai does not help after sleep, the Bavli connotes that it does.

Beis Yosef (DH Yesh): This connotes that people would drink only if they stipulated. However, it seems that the Rosh erred. The Bavli connotes that a Tanai does not help, and the Yerushalmi explicitly says that it helps!

Poskim

Shulchan Aruch (OC 564:1): Any fast in which one may eat the previous night, whether it is a Ta'anis Tzibur or private fast, he may eat and drink until dawn. This is if he did not sleep (Rema - Keva, i.e. in a fixed way).

Beis Yosef (DH v'Rabbeinu): R. Yerucham wrote like the Rosh, that all the more so if one slept b'Ones during the meal he may eat. Only Shinas Keva on a bed is called sleep. This is wrong. Surely, also not on a bed is Hesech ha'Da'as. We permit only dozing, or sleeping during the meal. The Ran holds like the Rosh.

Beis Yosef (DH Aval): The Magid Mishneh holds that the Rif forbids one who slept, even if he did not finish. This is difficult. If so, why did the Rif say that we are lenient, for this is mid'Rabanan? Each version has its leniency, like the Ran said! Perhaps the Magid Mishneh holds that the Rif holds that Version #1 forbids if he finished, and similarly if he slept, for this is like finishing. Version #2 forbids only if he slept. The Rif and Rambam connote like the Magid Mishneh, and so does the Sugya. The Ran's answer was only to resolve how Version #2 is lenient. Presumably, the Rambam rules like his Rebbi, the Rif, like he normally does. We hold like this. Why didn't the Rambam distinguish between sleeping and dozing? He did not need to, for Stam sleeping is proper sleep, and not dozing.

Taz (1): Shinas Keva is even not on a bed. Arai is only dozing. This is like the Beis Yosef, unlike R. Yerucham.

Taz (2): Since the Isur is mid'Rabanan, one may be lenient like the Rif to permit even if he slept Keva, as long as he did not finish his meal.

Magen Avraham (2): If he slept even during the meal (he may not finish).

Magen Avraham (1): One who fasts due to a frightening dream must fast from when he dreamed. The Shlah says that he should not have relations with his wife from the dream (for the rest of the night).

Gra (DH v'Hu): This is like the Rambam, like Version #2. It depends only on sleep.

Mishnah Berurah (3): Shinas Keva forbids even not on a bed. The Mechaber connotes that even sleep during the meal forbids. Several Acharonim permit, since he intended to eat more. One who is stringent is called Kadosh.

Kaf ha'Chayim (2): The Magen Avraham, Gra, Bigdei Yesha and Chayei Adam equate the Shulchan Aruch with what he wrote in the Beis Yosef, that the Rif holds like the Rambam, and forbids even after Shinas Keva during the meal. The Bach, Taz, Tur, Mishbetzos Zahav, Eliyahu Rabah and Aruch ha'Shulchan forbid only if he finished and slept.

Kaf ha'Chayim (4): One should not eat more than usual on the night before a fast.

Shulchan Aruch (ibid.): If he slept (Rema - Keva), he may not eat or drink, unless he stipulated to eat or drink.

Beis Yosef (DH v'Im): The Tur, Rosh citing R. Chananel, Ran, Tosfos, Mordechai and Semag say that a Tanai helps. Hagahos Maimoniyos brings from Tashbatz that our Gemara holds that a Tanai does not help. This is why it did not answer that the Beraisa discusses one who stipulated. Hagahos Maimoniyos says that perhaps the Gemara did not want to say that he stipulated, for this is obvious! If so, we can say that the Bavli and Yerushalmi agree. One may rely on all these who brought the Yerushalmi to be lenient, for it is a mid'Rabanan law.

Mishnah Berurah (4): One may stipulate after eating, as long as he did not sleep yet.

Kaf ha'Chayim (7): The Zohar and Mekubalim forbid eating after Shinas Keva until he prays (Shacharis). This does not depend on Tana'im, or whether or not he will fast.

Rema: Some say that no stipulation is needed for drinking. Presumably, a person intends to drink after sleeping. It is as if he stipulated.

Beis Yosef (DH Yesh): The Tur and Mordechai say that no Tanai is needed for drinking. Hagahos Maimoniyos brings so from Ohr Zaru'a and Semak. Hagahos Ashri connotes that Ohr Zaru'a permits all drinks. Kol Bo brings that R. Peretz permits only water. Tosfos (Shabbos 118a DH l'Fi) says that Riva permits drinking after sleeping based on the Yerushalmi, but the Ri did not want to be lenient, since the Bavli did not mention this. We are lenient to say that a Tanai helps, and one needs a Tanai even for drinking.

Magen Avraham (3): The Levush and Bach say that the custom is to stipulate even for drinking. This is proper. I say that if he normally drinks during the night, he need not stipulate.

Gra (DH v'Yesh): A Tanai helps because he did not yet accept the fast. The same applies to this (drinking, for presumably he intends to drink). The Beraisa connotes like this. It asks until when one may eat and drink, and says only that if he finished or slept, he may not eat. (It does not forbid drinking.)