Leviticus 1:7-9

and the sons of Aaron, the priest, must put fire on the altar and arrange wood on the fire. Then the sons of Aaron, the priests, must arrange the parts with the head and the suet on the wood that is in the fire on the altar. Finally, the one presenting the offering must wash its entrails and its legs in water and the priest must offer all of it up in smoke on the altar – it is a burnt offering, a gift of a soothing aroma to the Lord.