The vow-offering appears to have been a peace-offering vowed upon a certain condition; the voluntary-offering, one offered as the simple tribute of a devout heart rejoicing in peace with God and man offered on no external occasion (compare Leviticus 22:17-25).

But if the sacrifice of his offering be a vow,.... Be on account of a vow made, as, that if he was favoured with such and such benefits, or delivered out of such and such troubles and distresses, then he would offer such a sacrifice:

or a voluntary offering; without any condition or obligation; what from the mere motion of his mind he freely offered, not being directed to it by any command of God, or under any necessity from a vow of his own, and without any view to; any future good to be enjoyed: Aben Ezra describes both the one and the other thus; a "vow" which he uttered with his lips in his distresses, a "voluntary offering", which his spirit made him willing to bring, a sacrifice to God neither for a vow nor for thanksgiving:

it shall be eaten the same day that he offereth his sacrifice; that is, it shall be begun to be eaten then, and if all is eaten up it is very well, but they were not obliged in either of these cases, as in the preceding, to eat up all, and leave none to the morning, for it follows:

and on the morrow also the remainder of it shall be eaten; some of it, if thought fit, and could not be conveniently eaten, might be kept till the day after the sacrifice, but no longer.

But if the sacrifice of his offering be a {h} vow, or a voluntary offering, it shall be eaten the same day that he offereth his sacrifice: and on the morrow also the remainder of it shall be eaten:

(h) If he makes a vow to offer: or else the flesh of the peace offerings must be eaten the same day.

7:16 A vow - Offered in performance of a vow, the man having desired some special favour from God, and vowed the sacrifice to God if he would grant it. On the morrow also - Which was not allowed for the thank - offering.

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.