Leviticus 7:4-6

⁴And the two kidneys and the fat which is upon them, upon the inwards, and the caul that is upon the liver, with the kidneys, he shall take away.

⁵And the priest shall burn them at the altar, an oblation before the Lord; it is a trespass offering.

⁶Every man of the priests may eat thereof in the holy place; it is most sacred.