Leviticus 3:3-5

3:3 Then the one presenting the offering must present a gift to the Lord from the peace offering sacrifice: He must remove the fat that covers the entrails and all the fat that surrounds the entrails, 3:4 the two kidneys with the fat on their sinews, and the protruding lobe on the liver (which he is to remove along with the kidneys). 3:5 Then the sons of Aaron must offer it up in smoke on the altar atop the burnt offering that is on the wood in the fire as a gift of a soothing aroma to the Lord.

Leviticus 3:16

3:16 Then the priest must offer them up in smoke on the altar as a food gift for a soothing aroma – all the fat belongs to the Lord.