15 And the flesh of the sacrifice of his peace-offering of thanksgiving shall be eaten the same day that it is presented; he shall not let any of it remain until the morning. 16 And if the sacrifice of his offering be a vow, or voluntary, it shall be eaten the same day that he presented his sacrifice; on the morrow also the remainder of it shall be eaten; 17 and the remainder of the flesh of the sacrifice on the third day shall be burned with fire. 18 And if [any] of the flesh of the sacrifice of his peace-offering be eaten at all on the third day, it shall not be accepted, it shall not be reckoned to him that hath presented it; it shall be an unclean thing, and the soul that eateth of it shall bear his iniquity.
Matthew Henry's Commentary on Leviticus 7:15-18
Commentary on Leviticus 7:11-27
(Read Leviticus 7:11-27)
As to the peace-offerings, in the expression of their sense of mercy, God left them more at liberty, than in the expression of their sense of sin; that their sacrifices, being free-will offerings, might be the more acceptable, while, by obliging them to bring the sacrifices of atonement, God shows the necessity of the great Propitiation. The main reason why blood was forbidden of old, was because the Lord had appointed blood for an atonement. This use, being figurative, had its end in Christ, who by his death and blood-shedding caused the sacrifices to cease. Therefore this law is not now in force on believers.