Explanation: Wine of a Mitzvah is forbidden like optional wine. If one swore "I will drink [wine]", and afterwards vowed to be a Nazir, he is forbidden wine.

Distinction: Shaving is permitted for Tiglachas Metzora, like we say below (58a) from "Rosho". Tum'ah is permitted for a Mes Mitzvah.

Question: How could we learn from Tiglachas? The Torah [was stringent] to make one who shaves [a Nazir] like [a Nazir] who is shaved. Can you learn to wine, for which one who gives [to a Nazir] to drink is not like one who drinks?!

Answer: From this reason (the Kal va'Chomer), we would make one who gives to drink like one who drinks;

However, after we answer that [drinking] wine does not cancel, it is proper that we not make one who gives to drink like one who drinks, since it does not cancel.

Explanation: [R. Tarfon told R. Akiva] in Parshas Metzora, regarding the second shaving, it says "v'Hayah va'Yom ha'Shevi'i Yegalach Es Kol Se'aro v'Chibes Begadav ba'Mayim v'Taher; "Uva'Yom ha'Shmini Yikach Shenei Kevasim v'Kavsah Achas..."

I heard from you that a Metzora who shaved on the eighth day brings his Korban on the ninth! (Why do you permit a Nazir Tamei who shaved on day eight to bring Korbanos the same day?)

[R. Akiva answered] that this (a Nazir Tamei), his Taharah depends on days, after Haza'ah on days three and seven. A Metzora, his Taharah depends on shaving;

Even if [a Metzora] immersed on day seven, he must immerse again after shaving. If he did not shave until day eight, [after immersing] he is called a Tevul Yom, and he may not bring Korbanos unless he was Me'urav Shemesh (night came after he immersed);

The Torah was particular that he become Tahor from Tum'as Tzara'as upon bringing his Korbanos. If so, he cannot send his Korbanos [with a Shali'ach before ha'Arev Shemesh]. (Tosfos suggested through a Shali'ach, for he himself may not enter the Mikdash until ha'Arev Shemesh.)

Citation (Toras Kohanim) Suggestion: Perhaps [a Metzora] may immerse on the eighth day [when he brings Korbanos]. I.e., he may delay Tevilah until day eight.

Citation (cont.) Rejection: It says "u'Va Lifnei Hash-m." How can he come, unless he immersed during the day (yesterday) and had ha'Arev Shemesh?!

Question: Why is it obvious to the Tana that a Tevul Yom may not enter Machaneh Levi, and therefore he said "how can he come, unless he immersed during the day"?

A Tevul Yom of Zav (i.e. after immersing from Tum'as Zivah) may enter Machaneh Levi, like it says below! (We forbid only if he is Mechusar Kipurim. If not, e.g. he had only two emissions, and is exempt from a Korban, he is permitted.)

Answer: The Tana understands the verse "u'Va Lifnei Hash-m ba'Yom ha'Shmini" to imply that before the eighth day, he may not enter.

Explanation #1: So said Rav Noson bar Hoshaya's colleagues (that a Tevul Yom of Zav is like a Zav), since we find that the Tana holds that a Tevul Yom [of Zav] may not enter Machaneh Levi, even though a Tevul Yom from [Tum'as] Mes or Sheretz may;

Inference: The Tana holds that a Tevul Yom of Zav is like a Zav.

This affects whether or not we may slaughter and do Zerikah for him. If he delayed and did not immerse until the eighth day, he cannot send Korbanos, and we do not do Shechitah and Zerikah for him.

Source (Kerisus 10a): According to the opinion that a Tevul Yom of Zav is like a Zav, we do not slaughter and do Zerikah for him.

Explanation #2: I heard that they wanted to infer that a Tevul Yom [of Zav] is like a Zav since the Tum'ah came out of his body, even a Zav who had two emissions, who is not Mechusar Kipurim (he need not bring a Korban). He may not enter Machaneh Levi.

Explanation: Since they said Stam, and did not specify from where the Tana proves that a Tevul Yom may not enter Machaneh Levi...

You hold that he proves from the verse u'Va ba'Yom ha'Shmini, which implies that if he immersed on the eighth day, since he is a Tevul Yom, may not enter.

Note: The verse says "v'Hevi Osam ba'Yom ha'Shmini", which connotes that he himself enters.

Also regarding a Nazir, it is written in Parshas Nasa, regarding a Nazir Tamei "v'Gilach Rosho b'Yom Taharaso ba'Yom ha'Shevi'i Yegalchenu; uva'Yom ha'Shmini Yavi Shtei Turim Oh Shnei Bnei Yonah El ha'Kohen Pesach Ohel Mo'ed... v'Hevi Keves Ben Shenaso l'Asham..."

Also here, when does he bring? When he immersed and had ha'Arev Shemesh.