(Mishnah - Beis Shamai): If one said 'this cow said 'I will be a Nazir if I will get up' or 'this door said 'I will be a Nazir if I will be opened'', he is a Nazir;

Beis Hillel say, he is not a Nazir.

R. Yehudah says, Beis Shamai discuss only one who said 'this cow is Alai a Korban if it will stand.''

(Gemara) Objection: A cow cannot talk!

Answer #1 (Rami bar Chama): The case is, a cow was crouching in front of him: He said 'this cow thinks that it will not stand. I am a Nazir from its flesh if it stands on its own', and it stood on its own.

Beis Shamai and Beis Hillel are consistent with their opinions in the previous Mishnah.

Beis Shamai say that if one accepted to be a Nazir from dried figs and pressed dates, he is a Nazir. Also here, when he says that he will be a Nazir from its flesh, he is a Nazir. Beis Hillel say that he is not a Nazir.

Question: We can infer the law of our Mishnah from the previous Mishnah!

Answer (Rava, R. Chiya, and R. Oshaya): The same idea was taught two or three times (also regarding the door).

The repetition was necessary:

Had it taught only about figs and dates, one might have thought that only there Beis Shamai say that he is a Nazir, since these can be confused with grapes, but meat is not confused with grapes;

Had it taught only about meat, one might have thought that only there Beis Shamai say that he is a Nazir, since meat is associated with wine (people consume them together, or Ben Sorer u'Moreh, so they are commonly confused), but regarding figs and dates, it does not take effect. Therefore, it taught also figs and dates;

Had it taught only these two, one might have thought that Beis Shamai would agree in regarding a door that he is not a Nazir (a door has no connection to wine). Therefore it taught about a door;

Had it taught only about a door, one might have thought that Beis Hillel would agree that he is a Nazir regarding Peros or meat. Therefore, all cases needed to be taught.

Objection (Rava): The Mishnah does not say 'If it will get up by itself'!

Answer #2 (to Question (d) - Rava): Rather, the case is, a cow was crouching in front of him: He said 'It is Alai a Korban,'

Objection: This explains the case of the cow. How can we explain the case of the door? It cannot be a Korban!

Answer #3 (Rava): Rather, the case is, a cow was crouching in front of him: He said 'I am a Nazir from wine if it will not stand', and the cow stood on its own.

Beis Shamai explain, he himself intended to make the cow stand, and he did not do this (and therefore he is a Nazir).

Beis Hillel say that he just wanted that the cow should get up, and this was fulfilled.

Question (Seifa - R. Yehudah): Beis Shamai's law applies only if he said 'this cow is Alai a Korban...''

According to you, he did not try to forbid the cow!

Answer #4 (Rava): Rather, the case is, a cow was crouching in front of him: He said 'I am a Nazir from its flesh if it will not stand', and the cow stood on its own.

Beis Shamai explain, he himself intended to make the cow stand, and he did not do this (therefore he is a Nazir).

Beis Hillel say, he just wanted that the cow should get up, and this was fulfilled.

Question: How could Beis Hillel say that had it not risen, he would be a Nazir?

Version #1 (our text, Rashi): Beis Hillel hold that one who vowed to be a Nazir from its flesh is not a Nazir (just like one who said 'I am a Nazir from figs')!

Version #2 (Rosh's text): He vowed to be a Nazir from its flesh! (end of Version #2)

Answer: Beis Hillel address Beis Shamai according to Beis Shamai's reasoning:

Beis Hillel: We hold that even if it did not rise, he is not a Nazir.

Granted, you say he is a Nazir in that case. You should agree that his concern was that the cow get up (and any way it gets up, he is not a Nazir)!

Beis Shamai: No, his intent was to lift the cow himself.