Leviticus 7:29-32

²⁹Thou shalt also speak to the children of Israel, saying, He that offers a sacrifice of peace offering, shall bring his gift to the Lord also from the sacrifice of peace offering.

³⁰His hands shall bring the burnt offerings to the Lord; the fat which is on the breast and the lobe of the liver, he shall bring them, so as to set them for a gift before the Lord.

³¹And the priest shall offer the fat upon the altar, and the breast shall be Aaron’s and his sons,

³²and ye shall give the right shoulder for a choice piece to the priest of your sacrifices of peace offering.