(Continuation of Beraisa - Rebbi): You need not say so (that "Ta'ar" does not teach about the Isur, rather, about the Mitzvah to shave at the end. It teaches about both!)

"A Ta'ar will not pass over his head until completion (of Nezirus." This forbids a Ta'ar. We also infer that) after completion, a Ta'ar will pass over, i.e. he must shave with a Ta'ar.

Question: But it says "A Ta'ar will not pass over his head" (all forms of removing hair are forbidden)!

Answer: "Ta'ar" teaches that if he shaves with a Ta'ar, he transgresses two Isurim.

(Rav Chisda): One is lashed for shaving even one hair. Two unshaven hairs invalidate the Mitzvah of shaving (upon completion of Nezirus). If one shaved during Nezirus, he is Soser (nullifies days counted) only if he shaved the majority of his head. This (lashes) is only with a Ta'ar.

Question: The Beraisa says that one is liable for any method of removing hair!

Answer: Rather, Rav Chisda meant that one is liable only for shaving like with a Ta'ar (totally removing the hairs).

Support (regarding Stirah - Beraisa): If a Nazir pulled out any amount of hairs or parts of hairs, he is (Rosh's text - liable. He is) Soser only if he removed most of the hairs of his head with a Ta'ar; (According to the Rosh, this also supports Rav Chisda regarding lashes.)

R. Shimon says, just like two remaining hairs invalidate the Mitzvah of shaving (at the end), two hairs shaved during Nezirus are Soser.

(Mishnah): Three people have a Mitzvah to shave: a Nazir, a Metzora, and Leviyim (at the time they were chosen to serve the Mishkan);

All three must shave with a Ta'ar. Two remaining hairs invalidate the Mitzvah.

Question: The Torah explicitly says that they must shave! (Why did the Mishnah need to teach this?)

Answer: One might have thought that the Mitzvah is to remove the hair, and even a cream that makes hair fall out suffices. The Mishnah teaches that this is not so.

(Mishnah): They must shave with a Ta'ar.

Question: We understand regarding a Nazir. It says "A Ta'ar will not pass over his head (until completion"; after completion, a Ta'ar will pass);

Regarding Leviyim it says, "They will pass a Ta'ar over all their flesh."

Question: What is the source that a Metzora must shave with a Ta'ar?

Suggestion: Just like Tiglachas of Leviyim required a Ta'ar, also of Metzora'im.

Rejection: The Torah required the bodies of the Leviyim to be waved, but not of Metzora'im. Perhaps it is also more stringent about Tiglachas of Leviyim!

Suggestion: We learn from a Nazir.

Rejection: A Nazir brings breads with his Korban, unlike a Metzora. Perhaps Tiglachas Nazir is also more stringent than of a Metzora.

Answer: We learn from both of them.

We cannot learn from Leviyim alone. Since Leviyim needed to be waved, perhaps their Tiglachas is more stringent;

We learn from Nazir that Tiglachas with a Ta'ar applies even when the person need not be waved.

Objection: We cannot learn from a Nazir, because his Korban requires bread!

Answer: Leviyim required a Ta'ar, even though they did not bring bread!

The stringencies of Leviyim and Nezirim are different. The Tzad ha'Shavah (what is common to both) is that they must shave, and it must be with a Ta'ar. Also Metzora'im must shave; we learn that also they require a Ta'ar!

Rejection (Rava of Barnish): The Torah did not specify a cheaper Korban for poor Leviyim or Nezirim. We cannot learn to Metzora'im, for a poor Metzora brings a cheaper Korban!

Question (Rava bar Mesharshiya): The Tana first said (end of 39b) that we cannot learn that a Nazir must shave with a Ta'ar from a Metzora, since a Metzora is more stringent (apparently, he had an independent source for Metzora);

Later, the Tana (40a) tries (and fails) to learn a Metzora from a Nazir!

Answer (Rava): The former is like Chachamim; the latter is like R. Eliezer (as follows).

(Mishnah): One is liable (for shaving his beard) only with a Ta'ar;

R. Eliezer says, he is liable even with Melaket or Rehitani (tweezers or planing tools).

Question: What is the source of Chachamim?

Answer (Beraisa) Suggestion: Perhaps "(Kohanim) will not shave the corners of their beards" applies even to a Metzora!

Rejection: "(A Metzora will shave) Zekano" (even if he is a Kohen).

Question: How do we know that a Metzora must shave with a Ta'ar?

Answer (Beraisa) Suggestion: "(Kohanim) will not shave the corners of their beards" - Perhaps a Kohen is liable even if he shaves with scissors!

Rejection: "V'Lo Sashchis (totally cut off hairs)."

Suggestion: Perhaps one is liable even with a Melaket or Rehitani!

Rejection: "Lo Yegalechu (they will not shave)."

The Torah forbids shaving with Hashchasah, namely, with a Ta'ar. (Rambam - Melaket and Rehitani are both kinds of tweezers. Tosfos - they are planing tools. This is Hashchasah, but since people do not normally shave with them, this is not called Gilu'ach.)

Question: Perhaps the Isur is only with a Ta'ar, but a Metzora can also fulfill his Mitzvah with a Melaket or Rehitani, and "Zekano" permits him to shave with a Ta'ar!

Answer #1: If he fulfilled his Mitzvah with Melaket or Rehitani, no verse would be needed to permit a Ta'ar!

It is forbidden to become a Nazir, but even so a Nazir's Mitzvah to shave overrides the Isur to cut the Pe'os (sideburns). A Metzora did not sin, all the more so his Mitzvah to shave overrides the Isur to shave the beard (with a Ta'ar)!