Leviticus 6:17

It shall not be baked with leaven
Which, as it was a type of Christ, may denote his sincerity both in doctrine, life, and conversation; and as it may respect the offerer, may signify his uprightness and integrity, and his being devoid of hypocrisy and insincerity:

I have given it [unto thee for] their portion of my offerings made
by fire;
this was part of the provision made for the maintenance of the priests, as it was but just that they that ministered at the altar should live of it; and the rather, as the priests and Levites had no portion and inheritance in the land of Israel, and therefore must be supported in another way, which the Lord took care of:

it [is] most holy, as the sin [offering], and as the trespass
[offering];
as they, so this being devoted to sacred uses, what were not consumed upon the altar belonged to the priests, and were their perquisites, nor might they be appropriated to the use of any other.