Levítico 5:9

9 and is to splash some of the blood of the sin offering against the side of the altar; the rest of the blood must be drained out at the base of the altar. It is a sin offering.

9 and he shall sprinkle of the blood of the sin-offering upon the side of the altar; and the rest of the blood shall be drained out at the base of the altar: it is a sin-offering.