Leviticus 7:31-35

³¹the which shall burn the inner fatness upon the altar; soothly the breast shall be Aaron’s and his sons’;

³²and the right shoulder of the sacrifices of peaceable things shall turn into the first fruits of the priest.

³³He that of Aaron’s sons offereth the blood, and the inner fatness, shall have also the right shoulder in his portion.

³⁴For I have taken from the sons of Israel the breast of raising, and the shoulder of separating, of their peace-able sacrifices, and I have given those to Aaron the priest and to his sons, by everlasting law, of all the people of Israel.

³⁵This is the anointing of Aaron, and of his sons, that is, the offering in the day of their anointing, in the ceremonies of the Lord, in the day wherein Moses offered them, that they should be set in priesthood,