Speak unto the children of Israel, and say unto them, When a man shall make a {a} singular vow, the persons shall be for the LORD by {b} thy estimation.

(a) As of his son or daughter.

(b) Who art the priest.

Wesley's Notes

27:2 A singular vow - Or, an eminent, or hard vow, not concerning things, which was customary, but concerning persons, which he devoted to the Lord, which was unusual and difficult: yet there want not instances of persons who devoted either themselves or their children, and that either more strictly, as the Nazarites, and the Levites, 1Sam 1:11, and for these there was no redemption admitted, but they were in person to perform the service to which they were devoted: or more largely, as some who were not Levites, might yet through zeal to God, or to obtain God's help, which they wanted or desired, devote themselves or their children to the service of God and of the sanctuary, tho' not in such a way as the Levites, which was forbidden, yet in some kind of subserviency to them. And because there might be too great a number of persons thus dedicated, which might be burdensome to the sanctuary, an exchange is allowed, and the priests are directed to receive a tax for their redemption. By thy estimation - Thine, O man that vowest, as appears from Lev 27:8, where his estimation is opposed to the priest's valuation. Nor was there any fear of his partiality in his own cause, for the price is particularly limited. But where the price is undetermined, there, to avoid that inconvenience, the priest is to value it, as Lev 27:8,12.

Jamieson-Fausset-Brown Bible Commentary

2-8. When a man shall make a singular vow, &c.-Persons have, at all times and in all places, been accustomed to present votive offerings, either from gratitude for benefits received, or in the event of deliverance from apprehended evil. And Moses was empowered, by divine authority, to prescribe the conditions of this voluntary duty.

the persons shall be for the Lord, &c.-better rendered thus:-"According to thy estimation, the persons shall be for the Lord." Persons might consecrate themselves or their children to the divine service, in some inferior or servile kind of work about the sanctuary (1Sa 3:1). In the event of any change, the persons so devoted had the privilege in their power of redeeming themselves; and this chapter specifies the amount of the redemption money, which the priest had the discretionary power of reducing, as circumstances might seem to require. Those of mature age, between twenty and sixty, being capable of the greatest service, were rated highest; young people, from five till twenty, less, because not so serviceable; infants, though devotable by their parents before birth (1Sa 1:11), could not be offered nor redeemed till a month after birth; old people were valued below the young, but above children; and the poor-in no case freed from payment, in order to prevent the rash formation of vows-were rated according to their means.

Matthew Henry's Concise Commentary

27:1-13 Zeal for the service of God disposed the Israelites, on some occasions, to dedicate themselves or their children to the service of the Lord, in his house for life. Some persons who thus dedicated themselves might be employed as assistants; in general they were to be redeemed for a value. It is good to be zealously affected and liberally disposed for the Lord's service; but the matter should be well weighed, and prudence should direct as to what we do; else rash vows and hesitation in doing them will dishonour God, and trouble our own minds.