Leviticus 3:3-5

3Then 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,

4the two kidneys with the fat on their sinews, and the protruding lobe on the liver (which he is to remove along with the kidneys).

5Then 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.