Leviticus 1:9, 15

Its entrails, however, and its legs he shall wash with water. And the priest shall offer up in smoke all of it on the altar for a burnt offering, an offering by fire of a soothing aroma to the LORD.

The priest shall bring it to the altar, and wring off its head and offer it up in smoke on the altar; and its blood is to be drained out on the side of the altar.