Commentary for Leviticus 4:26

כחלב זבח השלמים [AND HE SHALL CAUSE ALL ITS FAT TO ASCEND IN FUMES], AS THE FAT OF THE SACRIFICE OF PEACE OFFERINGS — i. e. as those fat portions which are specified in the case of the goat that is mentioned among the peace-offerings (Leviticus 3:14, 15).

A goat. Rashi said “as those parts (אימורים)” instead of “as that fat” which would be understood [more directly] from the word [in the verse] “as the fat,” because Scripture does not intend to specify the fats. This is because the phrase, “all its fats” [already] includes all the fats. Rather, the verse’s intention is to add the lobe and the kidneys, which are not included in the statement, “all its fats.” Rashi [then] says: “which are detailed regarding a goat which is discussed [in the section dealing with] the peace-offering” because the peace-offering of a sheep also includes the tail fat among the אימורים, but the sin-offering of the leader is a goat, which has no tail fat.