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.

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.