Leviticus 1:7-9

7The sons of Aaron the priest will build a wood fire on the altar.

8They will arrange the pieces of the offering, including the head and fat, on the wood burning on the altar.

9But the internal organs and the legs must first be washed with water. Then the priest will burn the entire sacrifice on the altar as a burnt offering. It is a special gift, a pleasing aroma to the Lord.