Leviticus 9:18-21

18He slaughtered the bull and the ram for the people’s fellowship offering. Aaron’s sons gave him the blood, which he threw against the altar on all sides.

19However, the fat from the bull and the ram (the fat from the tail, the layer of fat, the kidneys, and the lobe of the liver)

20they placed on the breasts. Aaron burned them all on the altar.

21However, he first took the breasts and the right thighs and presented them to the Lord as Moses commanded.