(Mishnah - R. Meir): A Kal va'Chomer teaches this (if two witnesses can kill a man, all the more so they can be Mechayev him a Korban)!

Question: What is Chachamim's reason?

Do they say that one is believed about himself more than 100 witnesses (regarding atonement, for had he sinned, surely he would want to get a Kaparah)?

Or, Migo (since) he could have exempted himself by saying "I ate b'Mezid", he is believed to say "I did not eat". (Tosfos - we interpret this to mean 'I did not eat b'Shogeg, rather, b'Mezid.')

Question: What difference does it make which is the reason?

Answer: This determines the law of Tum'ah. (Two witnesses say "you became Tamei and entered the Mikdash", and he says "I did not become Tamei";)

If one is believed about himself more than 100 witnesses, this applies also to Tum'ah;

If he is believed because of the Migo, Chachamim would exempt only regarding an old Tum'ah (this will be explained), but not regarding a new Tum'ah.

Question: What is the reason?

Answer: Regarding an old Tum'ah, we can explain, "I did not become Tamei" to mean, "I did not remain Tamei, rather, I immersed (and became fully Tahor before entering the Mikdash)";

Regarding a new Tum'ah (e.g. the same day that he entered the Mikdash), we cannot explain this way. Even if he immersed before entering the Mikdash, he was still a Tevul Yom and is liable.

Answer #1 (to Question (b) - Beraisa): If one witness told Ploni, "you became Tamei (and entered the Mikdash)", and he denies it, he is exempt;

Suggestion: Perhaps the same applies if two witnesses told him that he became Tamei!

Rejection (R. Meir): Two witnesses can cause a man to be killed. All the more so they can obligate him to bring a Korban!

Chachamim: No. One is believed about his own (Chiyuv to bring a Korban for) atonement more than 100 witnesses.

This shows that Chachamim hold that one is believed about himself!

Rejection (R. Ami): No. Chachamim exempt due to the Migo;

Chachamim mean, because he could have said "I did not remain Tamei, rather, I immersed", he is believed about himself more than 100 witnesses.

Question: If so, this is just like Chelev! (Why was the same argument taught in a different case?)

Answer: One might have thought that "I did not eat" can be interpreted to mean, "I did not eat b'Shogeg, rather, b'Mezid" (for we merely add words), but we do not interpret "I did not become Tamei" to mean "I did not remain Tamei, rather, I immersed." The Beraisa teaches that we interpret even "I did not become Tamei."

Answer #2 (Beraisa): "V'Hisvadah" teaches that only one who confesses brings a Korban;

If one witness told Ploni "you became Tamei", and he denies it, he is exempt.

Suggestion: Perhaps the same applies if two witnesses told him that he became Tamei!

Rejection (R. Meir): Two witnesses can cause a man to be killed. All the more so they can obligate him to bring a Korban!

R. Yehudah: No. One is believed about himself more than 100 witnesses.

Chachamim agree with R. Yehudah regarding Chelev and entering the Mikdash, but not regarding Tum'ah (a Tamei who touched Taharos).

Question: What is the case?

If it is an old Tum'ah, Tum'ah is just like Chelev and Bi'as Mikdash. Just like Chachamim exempt the latter because he could have said "I was Mezid", regarding Tum'ah we can interpret his denial to mean "I did not remain Tamei, rather, I immersed"! (Rather, they argue about a new Tum'ah. R. Yehudah exempts, for he holds that one is believed about himself. Chachamim argue, for they hold that he is believed only due to the Migo! Rashi - Chachamim of the Beraisa are Chachamim of our Mishnah; Tosfos - R. Yehudah is like Chachamim of our Mishnah.)

Rejection (Ravina): Really, it refers to an old Tum'ah;

Version #1 (Rashi): The case is, the witnesses said that he ate Kodshim b'Tum'ah, and he said that he did not become Tamei. Chachamim do not interpret this to mean "I did not remain Tamei, rather, I immersed", for this is unlike his actual words;

"I did not become Tamei", implies that he did not eat Kodshim b'Tum'ah, and was not Metamei the meat (through touching it when Tamei). If we interpret his denial, i.e. only to exempt himself from the Korban (for eating b'Tum'ah), this is like admission that he was Metamei the meat!

Version #2 (Rashi): Chachamim believe him only regarding Kaparah, i.e. Chelev and Bi'as Mikdash (for which one brings a Korban), but not regarding touching.

Version #3 (Tosfos): Both R. Yehudah and Chachamim believe him only when we can interpret his words;

Chachamim interpret "I did not eat" to mean "I did not eat b'Shogeg, rather, b'Mezid", for this does not contradict what he said. We do not interpret "I did not become Tamei" to mean "I did not remain Tamei, rather, I immersed", for he said that he did not become Tamei at all.

(Rav Nachman): The Halachah follows R. Yehudah.

(Rav Yosef): (If witnesses said that Ploni was Metamei Taharos and he denies it,) R. Yehudah permits only Ploni to eat them (as if they are Tahor) himself, in private, lest others will be lax about Taharos.

(Reish Lakish): R. Meir agrees that if Ploni contradicts witnesses who say that he had relations with a Shifchah Charufah, he is believed, because he could have said that he was not Gomer (therefore, he is exempt. Surely, witnesses did not look so closely to see whether or not he was Gomer. Acharonim say that she cannot claim 'he did not finish the Bi'ah' to exempt herself from lashes, for there is a Chazakah that since she accepted warning for lashes, they finished the Bi'ah, or because she is lashed even for Ha'ara'ah due to Kedeshah (the Isur of any Shifchah to a Yisrael). See Teshuvas Chasam Sofer (4:103) and Or Some'ach Hilchos Isurei Bi'ah 1:19.)

(Rav Sheshes): R. Meir agrees that if a Nazir contradicts witnesses who say that he became Tamei, he is believed, because he could have said that he annulled his vow to be a Nazir.

(Abaye): R. Meir agrees that if one contradicts witnesses who say that (his Shevu'as ha'Edus was false, because) he knew a certain testimony, he is believed, because he could have said that when he saw the event, he did not intend to testify (later. Shitah asks that most testimony does not require that one intended to testify at the time he saw it! Tosfos learns from here that all testimony requires intent from the beginning. Mahari - he could have said that he forgot the testimony (he was not careful to remember it, because he did not plan to testify).)

(Mishnah): If one ate Chelev twice in one He'elem (he is liable only once).

Version #1 Question (R. Zeira): Why is he is liable only once? He ate two k'Zeisim!

Answer (Abaye): Ha'alamos are Mechalek. Here, it was all in one He'elem, so he brings only one Korban.

Version #2 - Inference: Had he eaten in two Ha'alamos, he would be liable twice.

Question: Why should he be liable twice for one (Shem) Isur?

Answer (Abaye): Ha'alamos are Mechalek.

Version #1 (Mishnah): If he ate Chelev, blood, Pigul, and Nosar... (if one ate two half-k'Zeisim of the same Min (Isur) in one He'elem, he is liable).

Objection: This is obvious!

Answer (Reish Lakish): The case is, he ate from two different plates. It is like R. Yehoshua, who says that plates are Mechalek. (If one Isur was cooked in different plates, each plate is considered a different Min);

One might have thought that R. Yehoshua says this to be stringent (if he ate a k'Zayis from each plate in one He'elem, it is as if he ate different Minim, he brings a Korban for each) and to be lenient (when he ate a half-k'Zayis from each, they are like different Minim and do not join). The Mishnah teaches that this is not so. He says this only to be stringent.

Version #2 (Seifa): If the half-k'Zeisim were of two Minim, he is exempt.

Objection: This is obvious!

Answer (Reish Lakish): The case is, he ate from two different plates. It is like R. Yehoshua, who says that plates are Mechalek;

One might have thought that R. Yehoshua says this only to be stringent, but not to be lenient. The Mishnah teaches that this is not so.

Question: What is the meaning of "two Minim"?

Answer: It is one Min (kind of Isur). It is called two because they were in two different plates;

This shows that R. Yehoshua holds that plates are Mechalek, even to be lenient.

Question: If the Seifa discusses one Min in two plates, the Reisha must discuss one Min in one plate. Obviously, he is liable!

Answer (Ravina): The case is, he found out in the middle (after eating a half-k'Zayis). The Mishnah is like R. Gamliel, who says Ein Yedi'ah l'Chatzi Shi'ur (finding out that he ate a half-Shi'ur does not prevent what he eats later (b'Shogeg) from joining to complete the Shi'ur);

(Mishnah - R. Gamliel): If (on Shabbos) one wrote two letters (in all, the Shi'ur to be liable for writing) in two Ha'alamos, one in the morning and one in the afternoon, he is liable;

Chachamim exempt.

R. Gamliel holds Ein Yedi'ah l'Chatzi Shi'ur. Chachamim hold Yesh Yedi'ah l'Chatzi Shi'ur (what he writes later is a separate He'elem. It does not join to complete the Shi'ur.)

(Mishnah) Question: How long can one delay while eating (Isur, and still be liable)?

Answer #1 (R. Meir): He can delay like one who eats crumbs (of parched grain);

Answer #2 (Chachamim): (He is liable) only if the delay from beginning to end was bi'Chdei Achilas Pras (within the time needed to eat half a standard loaf (Rashi - the size of eight eggs; Rambam - of six eggs). (Mid'Rabanan, if one ate a quarter loaf of Tamei food or drank a Revi'is of Tamei liquids, he becomes Tamei, and he may not eat Terumah until he immerses. This is a decree lest one put Terumah in his mouth while there is Tamei food inside.)

Version #1 (Rashi): If one ate (a quarter loaf of) Tamei food, drank (a Revi'is of) Tamei liquids, if the delay was bi'Chdei Achilas Pras, (he became Tamei);

If one drank a Revi'is of wine within this time and entered the Mikdash, he is liable.

Version #2 (in Shitah Mekubetzes 12): If one ate (a quarter loaf of) Tamei food, drank (a Revi'is of) Tamei liquids, or drank a Revi'is of wine and entered the Mikdash:

If the delay was bi'Chdei Achilas Pras, he is liable (mid'Oraisa for wine, and mid'Rabanan if he consumed Tamei food or drink).

R. Eliezer says, if he paused while drinking the wine, or added any water to it, he is exempt.

(Gemara) Question: Is R. Meir more lenient than Chachamim, or more stringent?

Does he mean that he can delay all day, like one who eats crumbs, even if the total time (Rambam; Rashi - the time between eatings) exceeds Kedei Achilas Pras? This is a stringency;

Chachamim reply that he is not liable unless he ate bi'Chdei Achilas Pras.

Or does he mean that he must eat without pausing, like one who eats crumbs, but if he paused he is exempt, even though he ate a Shi'ur within Kedei Achilas Pras. This is a leniency;

Chachamim reply that since he delayed at most Kedei Achilas Pras from beginning to end, he is liable.