The instructions for sin offering begin with its precise location. The opening command mandates that the sin offering is to be sacrificed at the same place as the burnt offering. According to Leviticus 1:11, the burnt offering is killed “on the north side of the altar” (see also Leviticus 4:24). This also applies to the sin offering. The point is that since forgiveness comes from the Lord, the purification offering must be brought before him.
18 Parle à Aaron et à ses fils, et dis: Voici la loi du sacrifice d'expiation. C'est dans le lieu où l'on égorge l'holocauste que sera égorgée devant l'Eternel la victime pour le sacrifice d'expiation: c'est une chose très sainte.