Leviticus 3:3-5

3From the sacrifice of the peace offerings, an offering by fire to the Lord, he shall present the fat that covers the entrails, and all the fat which is on the entrails,

4and 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.

5Aaron’s sons shall offer it up in smoke on the altar [placing it] on the burnt offering which is on the wood that is on the fire. It is an offering by fire, a sweet and soothing aroma to the Lord.