Leviticus 7:31; Leviticus 7:34

31 'The priest shall offer up the fat in smoke on the altar, but the breast shall belong to Aaron and his sons.

34 'For I have taken the breast of the wave offering and the thigh of the contribution from the sons of Israel from the sacrifices of their peace offerings, and have given them to Aaron the priest and to his sons as their due forever from the sons of Israel.