Leviticus 4:28-30

28if his sin which he has committed is made known to him, then he shall bring a goat, a female without blemish as his offering for the sin which he has committed.

29He shall lay his hand on the head of the sin offering [transferring symbolically his guilt to the sacrifice], and kill it at the place of the burnt offering.

30The priest shall take some of its blood with his finger and put it on the horns of the altar of burnt offering and shall pour out all the rest of its blood at the base of the altar.