Matthew Poole and continuators on Leviticus 7:35

35 This is the portion of the anointing of Aaron, and of the anointing of his sons, out of the offerings of the LORD made by fire, in the day when he presented them, to minister unto the LORD in the priests office.

(i. e.) Of the Priesthood, the sign put for the thing signified, and the anointing by a like figure is put for the right, or part, of the sacrifices belonging to the Priest by vertue of his anointing, as plainly appears from the words here following, out of the offerings, &c.

This was their portion appointed them by God in that day, and therefore to be given to them in after ages. Or, from the day, &c. and thence forward, the Hebrew preposition beth being put for min, as it is frequently.