1)
Why did Kohanim do Zerikah?
1.
'Rashi', Radak: From Kabalah and onwards, Kohanim must so Avodas ha'Dam.
2)
What do we learn from "mi'Yad ha'Leviyim"?
1.
'Rashi': The Leviyim did Shechitah, and not the owners, for most of Yisrael did not become Tehorim.
