Leviticus 3:3-5

From the sacrifice of the peace offerings he shall present an offering by fire to the LORD, the fat that covers the entrails and all the fat that is on the entrails, and the two kidneys with the fat that is on them, which is on the loins, and the lobe of the liver, which he shall remove with the kidneys. Then Aaron’s sons shall offer it up in smoke on the altar on the burnt offering, which is on the wood that is on the fire; it is an offering by fire of a soothing aroma to the LORD.