Leviticus 3:3

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,

Leviticus 3:5

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.