Leviticus 3:2 - Matthew Poole's English Annotations on the Holy Bible

At the door of the tabernacle of the congregation; not on the north side of the altar, where the burnt-offering was killed, Leviticus 1:11, as also the sin-offering, and the trespass-offering, Leviticus 6:25, Leviticus 7:2, but in the very entrance of the court where the Brazen altar stood, which place was not so holy as the other; as appears both because it was more remote from the holy of holies, and because the ashes of the sacrifices were to be laid here. And the reason of this difference is not obscure, both because part of this sacrifice was to be waved by the hands of the offerer, Leviticus 7:30, who might not come into the court; and because this offering was not so holy as the other, which were to be eaten only by the priest, when part of these were eaten by the offerer.