Leviticus 7:3-5

Amplified Bible

³ Then he shall offer all its fat, the fat tail and the fat that covers the entrails, ⁴ and the two kidneys with the fat that is on them at the loins, and the lobe of the liver, which he shall remove with the kidneys. ⁵ The priest shall offer them up in smoke on the altar as an offering by fire to the Lord; it is a guilt offering.