Komentarz do Kapłańska 9:2

קח לך עגל TAKE THEE A CALF — This animal was selected as a sin offering to announce to him that the Holy One, blessed be He, granted him atonement by means of this calf for the incident of the golden calf which he had made (Midrash Tanchuma, Shmini 4)

AND HE [Moses] SAID TO AARON: TAKE THEE A BULL-CALF FOR A SIN-OFFERING. Moses, our teacher, had been commanded about these offerings, as he said at the end [of the section], This is the thing which the Eternal commanded that ye should do,¹Verse 6. although this [command for these specific offerings] is not expressly mentioned. Similarly, And Moses said: This is the thing which the Eternal hath commanded: Let an omerful of it be kept throughout your generations,²Exodus 16:32. [where the verse indicates that Moses received a Divine command although it is not specifically mentioned]. Also, I am the G-d of Beth-el,³Genesis 31:13. when Jacob related [to his wives all that G-d’s angel had told him in the dream], even though it is not mentioned in Scripture that he was so told. I have already shown to you⁴Exodus 11:1. Also ibid., 12:21. many such examples in the sections on the commandments regarding the Passover.

קח לך עגל, "take for yourself a bull-calf, etc." Yuma 4 questions the need for the words "for yourself," seeing that the Torah goes on to say that the he-goat in verse 3 was for the people; obviously then the bull-calf was for Aaron personally. The Talmud answers that the words קח לך meant that Aaron was to pay for that bull-calf out of his personal funds.