Matthew Poole and continuators on Leviticus 6:23

23 For every meat-offering for the priest shall be wholly burnt: it shall not be eaten .

No part of it shall be eaten by the Priest, as it was when the offering was for the people. The reason of the difference is, partly because when he offered it for the people, he was to have some recompence for his pains, which he could not expect when he offered it for himself; partly to signifie the imperfection of the Levitical Priests, who could not bear their own iniquity; for the Priests eating part of the peoples sacrifices did signifie his typical bearing of the peoples iniquity, as appears from Levit. 10. 17. and partly to teach the Priests and Ministers of God, that it is their duty to serve God with singleness of heart, and to be content with Gods honour, though they have no present advantage by it.