Leviticus 4:16

when the sin in which they have sinned is known, then the assembly shall offer a young bull for a sin offering, and bring it before the Tent of Meeting.

The elders of the congregation shall lay their hands on the head of the bull before Yahweh; and the bull shall be killed before Yahweh.

and the priest shall dip his finger in the blood, and sprinkle it seven times before Yahweh, before the veil.

He shall put some of the blood on the horns of the altar which is before Yahweh, that is in the Tent of Meeting; and the rest of the blood he shall pour out at the base of the altar of burnt offering, which is at the door of the Tent of Meeting.