Leviticus 9:18-21

18He also killed the bull and the ram as sacrifices of peace offerings, which were for the people. And Aaron’s sons presented to him the blood, which he sprinkled all around on the altar,

19and the fat from the bull and the ram—the fatty tail, what covers the entrails and the kidneys, and the fatty lobe attached to the liver;

20and they put the fat on the breasts. Then he burned the fat on the altar;

21but the breasts and the right thigh Aaron waved as a wave offering before the Lord, as Moses had commanded.