A TEVUL YOM INVALIDATES THE AVODAH
(Mishnah): A Tevul Yom (is Mechalel Avodah).
Question: What is the source of this?
Answer (Beraisa - R. Simai): "Kedoshim Yihyu... v'Lo Yechalelu" hints that a Tevul Yom is Mechalel Avodah:
Since we already know that a Tamei is Mechalel Avodah from "va'Yinazru...", we use this verse to teach about a Tevul Yom.
Question: Why don't we use it to teach that a Kohen who tore his hair or shaved the corners of his beard (the Mitzvos written just before "Kedoshim Yihyu") is Mechalel Avodah?
Answer: We learn that a Tevul Yom is Chayav Misah for Avodah from a Gezerah Shavah "Chilul-Chilul" (from Terumah to this verse), therefore, we only learn that one who disqualifies Terumah is Mechalel Avodah.
Question (Rabah): Why must the Torah teach separately that a Tamei, Tevul Yom and Mechusar Kipurim are Mechalel Avodah?
Answer: Had it taught only about a Tamei, we would have thought that this is because he is Metamei;
Had it taught only about a Tevul Yom, we could not have learned to Mechusar Kipurim, who is permitted to eat Terumah;
Had it taught only about a Mechusar Kipurim, we could not have learned about a Tevul Yom, for he becomes (fully) Tahor automatically.
Suggestion: Granted, none of these three could teach the other two. Perhaps one of them could be learned from the other two!
Question: Which could be learned from the others?
We cannot learn Mechusar Kipurim from the others, for they are forbidden to eat Terumah;
Suggestion: We can learn Tevul Yom from the (Tzad ha'Shavah of the) others.
Question: They do not become Tahor automatically!
Answer: The Tum'ah of Mechusar Kipurim became lighter (he already immersed), so all he needs is a Korban. Since a Tamei does not need a Korban, we can learn from the Tzad ha'Shavah.)
Rejection: He holds that a Zav who (completed most of the Taharah process but still) is Mechusar Kipurim is like a (fully Tamei) Zav. (Rashi - he is Chayav Kares for eating Kodshim or entering the Mikdash, and he is Metamei Kodshim like a Zav; Tosfos - even when most of Yisrael are Tamei Mes and are permitted to bring Korban Pesach in Tum'ah, he is forbidden.)
Suggestion: Tana'im argue about whether a Zav who is Mechusar Kipurim is like a Zav.
(Beraisa): If an Onen or Mechusar Kipurim burned the Parah Adumah, it is Kosher;
Yosef ha'Bavli says, if an Onen burned it, it is Kosher. If a Mechusar Kipurim burned it, it is Pasul.
Suggestion: Yosef ha'Bavli holds that a Zav who is Mechusar Kipurim is like a Zav. The first Tana holds that he is not like a Zav.
Rejection: No, all agree that he is not like a Zav;
They argue about "v'Hizah ha'Tahor", which teaches that even one who is (partially) Tamei (i.e. Tevul Yom) is Kosher for the Parah Adumah;
The first Tana holds that this refers to (Tevul Yom of) all Tum'os;
Yosef ha'Bavli says that it only refers to (Tevul Yom of) the Tum'ah of this Parshah, i.e. Tum'as Mes (or lighter Tum'os);
Zav is more stringent, for the Tum'ah emanates from the person himself.
(Mishnah): Mechusar Begadim (is Mechalel Avodah).
Question: What is the source of this?
Answer (R. Avuha): "V'Chagarta Osam Avnet Aharon u'Vanav... Migva'os v'Haysah Lahem Kehunah l'Chukas Olam" - they are Kohanim only when their clothes are on them.
Question: We learn from a different verse!
(Beraisa) Question: What is the source that Shtuyei Yayin (a Kohen who drank wine) is Mechalel Avodah?
Answer: "Yayin v'Shechar Al Tesht... u'Lehavdil Bein ha'Kodesh u'Vein ha'Chol" (Avodah done while drunk is Chol (profane)).
Question: What is the source that Mechusar Begadim or one who did not wash his hands and feet is Mechalel Avodah?
Answer: We learn from a Gezerah Shavah "Chukah-Chukah".
Answer: From there, we would know only Avodos for which a Zar is Chayav Misah;
"V'Chagarta..." teaches all Avodos.