Leviticus 27:2-8

“Speak to the people of Israel and say to them, If anyone makes a special vow to the LORD involving the valuation of persons, then the valuation of a male from twenty years old up to sixty years old shall be fifty shekels of silver, according to the shekel of the sanctuary. If the person is a female, the valuation shall be thirty shekels. If the person is from five years old up to twenty years old, the valuation shall be for a male twenty shekels, and for a female ten shekels. If the person is from a month old up to five years old, the valuation shall be for a male five shekels of silver, and for a female the valuation shall be three shekels of silver. And if the person is sixty years old or over, then the valuation for a male shall be fifteen shekels, and for a female ten shekels. And if someone is too poor to pay the valuation, then he shall be made to stand before the priest, and the priest shall value him; the priest shall value him according to what the vower can afford.