Leviticus 7:4-6

⁴both kidneys with the fat on them by the loins, and the best part of the liver, which the priest is to remove together with the kidneys.

⁵He shall burn them on the altar as a food offering to the Lord; it is a guilt offering.

⁶Any male among the priests may eat it. It must be eaten in a holy place, it is most holy.