1)
For which sin did the Levi'im require atonement?
1.
Rashi: Refer to 8:7:2:1.
2.
Moshav Zekenim, citing R. Eliezer of Garmaiza: It was the sin of [killing the people of] Shechem ("va'Yikchu? Shimon v'Levi " ? Bereishis 34:25). We do not find that they had another sin. In Mitzrayim, only they fulfilled Bris Milah ? "u'Brischa Yintzoru" (Devarim 33:9). At the Egel, none of them sinned (Sh'mos 32:26)