2 “Speak to the Israelites and tell them, ‘When a man makes a special votive offering based on the conversion value of persons to the Lord, 3 the conversion value of the male from twenty years old up to sixty years old is fifty shekels by the standard of the sanctuary shekel. 4 If the person is a female, the conversion value is thirty shekels. 5 If the person is from five years old up to twenty years old, the conversion value of the male is twenty shekels, and for the female ten shekels. 6 If the person is one month old up to five years old, the conversion value of the male is five shekels of silver, and for the female the conversion value is three shekels of silver. 7 If the person is from sixty years old and older, if he is a male the conversion value is fifteen shekels, and for the female ten shekels. 8 If he is too poor to pay the conversion value, he must stand the person before the priest and the priest will establish his conversion value; according to what the man who made the vow can afford, the priest will establish his conversion value.Leviticus 27:2-13
9 “‘If what is vowed is a kind of animal from which an offering may be presented to the Lord, anything which he gives to the Lord from this kind of animal will be holy. 10 He must not replace or exchange it, good for bad or bad for good, and if he does indeed exchange one animal for another animal, then both the original animal and its substitute will be holy. 11 If what is vowed is an unclean animal from which an offering must not be presented to the Lord, then he must stand the animal before the priest, 12 and the priest will establish its conversion value, whether good or bad. According to the assessed conversion value of the priest, thus it will be. 13 If, however, the person who made the vow redeems the animal, he must add one fifth to its conversion value.
This is part of the law concerning singular vows, extraordinary ones; which though God did not expressly insist on, yet if they were consistent and conformable to the general precepts, He would be well pleased with. Note — We should not only ask what must we do, but what may we do, for the glory and honour of God. As the liberal devise liberal things (Isaiah 32:8), so the pious devise pious things, and the enlarged heart would willingly de something extraordinary in the service of so good a Master as God is. When we receive or expect some singular mercy, it is good to honour God with some singular vow.