Leviticus 27:1-10

The LORD said to Moses, “Speak to the Israelites and say to them: ‘If anyone makes a special vow to dedicate a person to the LORD by giving the equivalent value, set the value of a male between the ages of twenty and sixty at fifty shekels of silver, according to the sanctuary shekel; for a female, set her value at thirty shekels; for a person between the ages of five and twenty, set the value of a male at twenty shekels and of a female at ten shekels; for a person between one month and five years, set the value of a male at five shekels of silver and that of a female at three shekels of silver; for a person sixty years old or more, set the value of a male at fifteen shekels and of a female at ten shekels. If anyone making the vow is too poor to pay the specified amount, the person being dedicated is to be presented to the priest, who will set the value according to what the one making the vow can afford. “ ‘If what they vowed is an animal that is acceptable as an offering to the LORD, such an animal given to the LORD becomes holy. They must not exchange it or substitute a good one for a bad one, or a bad one for a good one; if they should substitute one animal for another, both it and the substitute become holy.