Charles Ellicott Commentary Leviticus 7:2

"In the place where they kill the burnt-offering shall they kill the trespass-offering; and the blood thereof shall he sprinkle upon the altar round about." — Leviticus 7:2 (ASV)

In the place where they kill. —That is, the north side of the altar (Leviticus 1:11).

Shall they kill the trespass offering. —That is, the people who bring these sacrifices are to kill them, since the offerers themselves slaughtered the victim .

The blood thereof shall he sprinkle. —Better, throw the blood .

Unlike the sin offering, whose blood was thrown upon the horns of the altar (Leviticus 4:25, 30, 34), the blood of the trespass offering was simply thrown upon the walls of the altar, or around it .

During the Second Temple, there was a scarlet line or thread around the altar, exactly in the middle. The blood of the trespass offering and of the peace offering was thrown around below the central line, while that of the whole burnt offering was thrown around above the central line.