Leviticus 9:18-21

18He also killed the bull and the ram, the sacrifice of peace offerings which was for the people; and Aaron’s sons handed the blood to him and he sprinkled it around on the altar,

19As for the portions of fat from the bull and from the ram—the fat tail, and the fat covering the internal organs, and the kidneys, and the lobe of the liver—

20they now put the portions of fat on the breasts; and Aaron offered the fat up in smoke on the altar.

21But the breasts and the right thigh Aaron presented as a wave offering before the Lord, just as Moses had commanded.