פירוש על שמות 29:33

ואכלו אתם AND THEY SHALL EAT THOSE THINGS i. e. Aaron and his sons because they are the “owners” of them (cf. Pesachim 59b).

ואכלו אותם אשר כפר בהם, "and they will eat them with which atonement was made." They will eat those parts of the animal in their capacity as owners and not in their capacity as priests. The meaning of the words אשר כפר בהם is that the consumption of meat of the peace-offerings by their owners confers atonement upon them. Even Moses was forbidden to eat of any of these parts of the animal, though he was permitted to eat the breast and the thigh.

Through which atonement was achieved. . . “strange” and objectionable. I.e., everything strange and objectionable that Aharon and his sons did was atoned for them through this ram of the completion-offering and this bread. [Rashi knows this] because otherwise, [if כֻפַר referred to Aharon and his sons, and not to everything “strange and objectionable”,] it should say אשר כֻפְרו בהם (plural).