Kommentar zu Schemot 29:36

על הכפרים means for the purpose of expiation — to expiate for the altar for all that is “strange” (not holy) and objectionable that may happened to it. Now since it is said. (v. 35) “Seven days shalt thou consecrate them” after having stated that if a single thing is omitted the ceremony is invalid, I can infer nothing more than that this alludes to a thing that is offered on account of them personally as, for example, the rams and the bread, but as regards anything that is offered on account of the altar as, for example, the bullock, which is intended to serve as expiation for the altar, we cannot infer from that verse that if this is omitted the ceremony of initiation is invalid; consequently this verse is necessary to inform us of this. An explanation in Torath Cohanim (the Sifra) states: atonement for the altar was necessary because perhaps a man had donated for work in connection with the construction of the Tabernacle or the altar something which he had stolen (Sifra, Tzav, Mechilta d'Miluim 1 15).

AND EVERY DAY SHALT THOU OFFER THE BULLOCK OF SIN-OFFERING ‘AL HAKIPURIM’ — “for atonement, to atone for the altar for anything strange [i.e., unholy] and abominable [that may happen to be brought upon it]. And in the Midrash of Torath Kohanim²¹⁸Sifra Tzav, Milu’im 1:15. it says: ‘atonement for the altar was necessary in case a person had donated for work in connection with the construction of the Tabernacle and [the sacrifices brought upon] the altar something he had acquired by robbery’” [or other unlawful means]. This is the language of Rashi. The correct interpretation of al hakipurim is, however, [that he is to bring the bullock of sin-offering] in addition to the two rams²¹⁹One was a burnt-offering (Verses 16-18) and the other — the ram of consecration — was a peace-offering, as explained by Ramban above in Verse 31. which were an atonement for Aaron and his sons, as He said here, And they shall eat those things wherewith atonement was made,²²⁰Verse 33. and surely the [bullock] sin-offering was for the purpose of atonement. And it is further written, As hath been done this day, so the Eternal hath commanded to do, to make atonement for you.²²¹Leviticus 8:34. This verse shows that all three sacrifices [the bullock sin-offering, the ram burnt-offering, and the ram peace-offering] brought on each of the seven days of consecration were for the purpose of making atonement. Thus it is seen that there was atonement in all the three sacrifices. Such are the words of Rabbi Abraham ibn Ezra.

ופר חטאת תעשה ליום על הכפורים, “and one bull shall you make as a sin offering on each of these days of the consecration rites.” The atonement was required in respect of non-consecrated people having performed service on the altar. (or according to the Midrash anyone whose donation to the materials of the Tabernacle having donated materials not legally his.) Nachmanides considers these words as referring back to the words אשר כופר בהם, in verse 33, in case during eating any of the parts of these sacrifices an inadvertent halachic error had been committed by either Aaron or one of his sons. Although a sin offering is always the catalyst of atonement, in this instance, there was an innovation in that even the rams also conferred atonement of their owners.