When thou vowest a vow unto God,.... Or "if thou vowest" , as the Vulgate Latin version; for vows are free and indifferent things, which persons may make or not; there is no precept for them in the word of God; instances and examples there are, and they may be lawfully made, when they are in the power of man to perform, and are not inconsistent with the will and word of God; they have been made by good men, and were frequent in former times; but they seem not so agreeable to the Gospel dispensation, having a tendency to ensnare the mind, to entangle men, and bring on them a spirit of bondage, contrary to that liberty wherewith Christ has made them free; and therefore it is better to abstain from them: holy resolutions to do the will and work of God should be taken up in the strength of divine grace; but to vow this, or that, or the other thing, which a man previous to his vow is not obliged unto, had better be let alone: but however, when a vow is made that is lawful to be done,defer not to pay it; that is, to God, to whom it is made, who expects it, and that speedily, as Hannah paid hers; no excuses nor delays should be made;for [he hath] no pleasure in fools; that is, the Lord hath no pleasure in them, he will not be mocked by them; he will resent such treatment of him, as to vow and not pay, or defer payment and daily, with him.
So the Targum,"for the Lord hath no pleasure in fools, because, they defer their vows, and do not pay;''pay that which thou hast vowed; precisely and punctually; both as to the matter, manner, and time of it.
rdt rvak "si quid vovisti", V.