15 And the flesh of the praise-offering is to be taken as food on the day when it is offered; no part of it may be kept till the morning. 16 But if his offering is made because of an oath or given freely, it may be taken as food on the day when it is offered; and the rest may be used up on the day after: 17 But if any of the flesh of the offering is still unused on the third day, it is to be burned with fire. 18 And if any of the flesh of the peace-offering is taken as food on the third day, it will not be pleasing to God and will not be put to the account of him who gives it; it will be unclean and a cause of sin to him who takes it as food.
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.