Leviticus

But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the Lord.

And he shall lay his hand upon the head of his offering, and kill it at the door of the tabernacle of the congregation: and Aaron’s sons the priests shall sprinkle the blood upon the altar round about.

And he shall lay his hand upon the head of it, and kill it before the tabernacle of the congregation: and the sons of Aaron shall sprinkle the blood thereof upon the altar round about.

And he shall take away all the fat thereof, as the fat is taken away from off the sacrifice of peace offerings; and the priest shall burn it upon the altar for a sweet savour unto the Lord; and the priest shall make an atonement for him, and it shall be forgiven him.

And the priest shall burn it upon the altar: it is the food of the offering made by fire unto the Lord.