Leviticus 7:32-34 and you shall give the right shoulder for a choice piece to the priest of your sacrifices of peace-offering.

CAB⁽ⁱ⁾ ³² and you shall give the right shoulder for a choice piece to the priest of your sacrifices of peace-offering. ³³ He that offers the blood of the peace-offering, and the fat, of the sons of Aaron, his shall be the right shoulder for a portion. ³⁴ For I have taken the wave-breast and shoulder of separation from the children of Israel from the sacrifices of your peace-offerings, and I have given them to Aaron the priest and his sons, a perpetual ordinance due from the children of Israel.