What is the Pasuk referring to when it writes "Ach el ha'Paroches Lo Yavo" and "v'El ha'Mizbe'ach Lo Yigash"?
Rashi: It is referring the seven sprinklings that take place on Yom Kipur and approaching the Mizbe'ach ha'Olah 1 to bring Korbanos, respectively.
See Sifsei Chachamim.
Why does the Pasuk need to mention both the Paroches and the Mizbe'ach?
Rashi and Da'as Zekenim, citing Toras Kohanim: The Paroches is inside the Heichal, so we cannot learn the Mizbe'ach from it. The Mizbe'ach is designated for the Avodah, so we could not learn from it going to the Paroches.
What does "Ach" come to preclude?
What are the connotations of "v'Lo Yechalel es Mikdashai"?
Rashi: If a Ba'al Mum served, his Avodah is Pasul.
Rashi (in 20:3): Mikdashai refers to K'nesses Yisrael, who are sanctified to Hashem.
Seeing as the prohibition of Ba'alei-Mumin is confined to the Kohanim, why does the Pasuk insert "Kol Bnei Yisrael"?
Rashi: To warn Beis-Din to make sure that the Kohanim observe it.
Rashi learns from "v'Lo Yechalel" that if a Ba'al Mum served, his Avodah is Pasul. Kidushin 66b learns this from "Es Brisi Shalom" (Bamidbar 25:13) - when he is Shalem, and not lacking!
Moshav Zekenim: The verse here implies that if he served b'Mezid, it is Pasul. "Brisi Shalom" teaches that even b'Shogeg, it is Pasul.
Keren Orah (Ta'anis 17a): "Barech Hashem Cheilo" (Devarim 33:11) teaches that if we find that a Kohen was a Chalal, b'Di'eved his Avodah is Kosher (Pesachim 72b). One might have thought that the same applies to a Ba'al Mum's Avodah; the extra verse teaches that this is not so.
Rashi learns from "v'Lo Yechalel" that if a Ba'al Mum served, his Avodah is Pasul. This is like R. Chanina ben Gamliel, who infers the positive from the negative. What is the source for R. Meir, who does not infer?
Shevu'os 36b: For Isur, R. Meir agrees that from the negative you infer the positive. 1
Why did Moshav Zekenim, citing R. Yehudah ha'Chasid, leave this difficult? The Rishonim cite different texts in Shevu'os 36b. Perhaps in his text, R. Meir infers the positive from the negative only for a severe Isur; Chachamim hold that there is no Misah for a Ba'al Mum who served (Tosefta Zevachim 12:17. - PF)