Exodus 29:22

החלב THE FAT — This means the fat of the gut, or, (according to the opinion of Rabbi Ishmael,) of the maw (Chullin 49b; cf. Rashi on Leviticus 3:3). והאליה AND THE FAT TAIL — This is the portion of the animal from the kidneys and lower down, as is explained in Leviticus, (3:9) because it is said, “[the whole fat tail], he shall take it off hard by the back bone (עָצָה)” i. e. by the place where the kidneys give counsel (עָצָה) (Chullin 11a). In the case of the fat portions of the bullock the “fat tail” is not mentioned, for the “fat tail” was offered only in the case of a male or female lamb and a ram, but an ox and a goat do not require the “fat tail” to be offered. ואת שוק הימין AND THE RIGHT SHOULDER — We do not find that burning if prescribed for the right shoulder together with the fat parts except in the case of this alone. כי איל מלאים הוא FOR IT IS A RAM OF מלאים — of שלמים (usually translated peace-offerings): מלואים has the meaning of “perfection” (מלא meaning “full”, so that מלואים is synonymous with שלמים) — something that is perfect in all respects. Scripture informs us that the מלואים (consecration sacrifices) are to be regarded as שלמים-sacrifices, in that they, like the שלמים, promote peace (שלום) between the altar and him who carries out the sacrifical rite (the priest) and the owner of the animal (the worshipper who brings the sacrifice”). Therefore, says God, in this case I make it a condition that the breast shall belong as a portion to him who performs the sacrificial rite, viz., Moses, who officiated at the installation into office (cf. v. 26). — The remainder, Aaron and his sons ate because they were the “owners”, as is expressly set forth in this section (cf. Sifra, Vayikra Dibbura d'Nedavah, Chapter 16 2; Midrash Tanchuma, Tzav 4).

וְלָקַחְתָּ֣ מִן־הָ֠אַ֠יִל הַחֵ֨לֶב וְהָֽאַלְיָ֜ה וְאֶת־הַחֵ֣לֶב ׀ הַֽמְכַסֶּ֣ה אֶת־הַקֶּ֗רֶב וְאֵ֨ת יֹתֶ֤רֶת הַכָּבֵד֙ וְאֵ֣ת ׀ שְׁתֵּ֣י הַכְּלָיֹ֗ת וְאֶת־הַחֵ֙לֶב֙ אֲשֶׁ֣ר עֲלֵיהֶ֔ן וְאֵ֖ת שׁ֣וֹק הַיָּמִ֑ין כִּ֛י אֵ֥יל מִלֻּאִ֖ים הֽוּא׃

Also thou shalt take of the ram the fat and the fat tail, and the fat that covers the inwards, and the appendage of the liver, and the two kidneys, and the fat that is upon them, and the right shoulder; for it is a ram of consecration: