Sforno on Leviticus 6:18/ספורנו על ויקרא ו׳:י״ח

1now the “Torah” of the sin offering, חטאת, is mentioned. If the sin offering is meant to atone for a serious sin, its blood has to offered in side the sanctuary, and none of the offering is allocated to the priests to eat. The parts normally eaten by the priests will also be burned.