Midrash su Levitico 16:15

1) (Vayikra 16:15) ("And he shall slaughter the he-goat of the sin-offering which is the people's, and he shall bring its blood inside the curtain; and he shall do with its blood as he did with the blood of the bullock, and he shall sprinkle it upon the ark cover and before the ark cover."): "And he shall slaughter the he-goat of the sin-offering which is the people's": His fellow Cohanim are not to receive atonement through it. And through what is this atonement effected? Through the bullock of their brothers. I might think that their atonement is not effected through that of their brothers, it being written (Vayikra 16:6) ("the bullock) which is his" (Aaron's), which implies that they do not have atonement through it. But (Vayikra 16:33) "And for the Cohanim and for the entire people of the congregation he shall make atonement" indicates that they do have atonement. Through what, then, is this atonement effected? It is better that they have atonement through the bullock of their brother Cohanim — For we find that part of the criterion ("which is his" [i.e., Aaron's] Vayikra 16:6) was separated (from the literal "his"), finding as we do that (both) he and his family receive atonement through it — than that they receive atonement through the bullock of the congregation, where we find no such separation from the criterion. And, if you will, it may be derived thus (Vayikra 16:6) "And Aaron shall present the bullock of the sin-offering which is his, and he shall make atonement for himself and for his household," and they (the Cohanim) are (part of) the household of Aaron, as it is written (Tehillim 235:19): "House of Aaron (i.e., the Cohanim) — Bless the L–rd!"

2) "and he shall bring its blood inside the curtain": We are hereby taught that he enters with it into the holy of holies. This tells me (that he does so) only with the blood of the he-goat. Whence is the same derived for the blood of the bullock? From "and he shall do with its blood as he did with the blood of the bullock." — Just as he enters into the holy of holies with the blood of the he-goat, so he enters into it with the blood of the bullock.

3) "and he shall sprinkle it upon the ark cover": We are hereby taught that he applies one above (i.e., upon the ark cover). "and before the ark cover": I would not know how many. (But) I derive it as follows: Application of the blood below is mentioned in respect to the bullock, and application of the blood below is mentioned in respect to the he-goat. Just as with the first there are seven (applications), so, with the second.