(Mishnah): There are two primary kinds of SHEVUOS (of Bituy). There are four in all;

[The primary two are] 'I swear that I will eat' and 'I swear that I will not eat.' [The others are] 'I swear that I ate' and 'I swear that I did not eat.'

R. Akiva says, if one swore 'I will not eat' and he ate Mashehu (any amount), he is liable;

Chachamim: We never find that someone is liable for eating Mashehu. How can he be liable?!

R. Akiva: We never find that one brings a Korban for speaking! (The Korban is for transgressing his words. His intention was not to eat at all. If he eats Mashehu he transgressed!)

(Gemara) Question: Granted, [one is liable for] 'I will eat' and 'I will not eat.' What is the case of 'I ate' and 'I did not eat'?

If it is known [to him] that he ate, and he swore that he did not eat, this is Shevu'as Sheker (i.e. he is Mezid, and there is no Korban)!

Suggestion: He thinks that he did not eat, and he swore that he did not eat.

Rejection (R. Ba bar Rav Yehudah citing Rav): [A Mishnah teaches that one is liable for Shevu'as ha'Edus whether he was Mezid or Shogeg about the Shevu'ah, and Mezid about not knowing testimony. This means that] he was Shogeg about [Chiyuv] Korban [for the Shevu'ah] and Mezid about the testimony, but if he says "I thought that there is no [Isur of a false] Shevu'ah, it is permitted (he is totally exempt. This is Ones! The same applies if he thought that he swore Emes.)

Answer #1: Rather, he was Mezid about it (the Shevu'ah), and Shogeg about the Korban.

Support: Didn't R. Avahu say in the name of R. Yochanan that if one ate Chelev Mezid but he was Shogeg about the Korban, they warn him, and he is lashed and brings a Korban?

Objection: You cannot say so, for R. Lo said in the name of R. Lazar, so R. Yishmael answered R. Akiva - "do we find that someone is liable [lashes] for Mezid for Shevu'as Sheker, and [Chayav Korban] b'Helam, due to Bituy?!"...

And R. Akiva answered him "we find that someone is liable for Mezid for Shevu'as Sheker, and he brings a Korban!" (According to R. Yochanan, R. Akiva should have answered that for Chatas Chelev [or any other Lav with Kares], there are lashes for Mezid and Korban, if he was Shogeg about the Korban!)

Answer #2: Rather, we discuss one who is sure that he ate, and swore that he did not eat (and later realized that he erred).

Objection: Is this not like one who said "this is not a [forbidden] Shevu'ah"? (We said above that since he thinks that it is permitted, this is Ones, and he is exempt!)

Answer: There, he said "this is not a [forbidden] Shevu'ah." However, here he knows that it is [forbidden to take a false] Shevu'ah, just he errs due to something else (whether or not he ate).

Question: What is the case [in which they argue about being liable for Mashehu]?

If he said "I swear that I will eat Achilah of the Torah", even R. Akiva admits [that he is not liable for less than a k'Zayis]!

If he said "I swear that I will not taste", even Rabanan agree!

Answer: Rather, we discuss [that he swore] Stam.

Question: [Does R. Akiva hold that] Kol she'Hu is considered Achilah?!

Answer: [Indeed,] we answer [that R. Akiva holds] like R. Shimon, who says that Kol she'Hu is considered Achilah. (We explained this like KORBAN HA'EDAH.)