Leviticus 27:1-10

The LORD said to Moses, “Give the following instructions to the people of Israel. If anyone makes a special vow to dedicate someone to the LORD by paying the value of that person, here is the scale of values to be used. A man between the ages of twenty and sixty is valued at fifty shekels of silver, as measured by the sanctuary shekel. A woman of that age is valued at thirty shekels of silver. A boy between the ages of five and twenty is valued at twenty shekels of silver; a girl of that age is valued at ten shekels of silver. A boy between the ages of one month and five years is valued at five shekels of silver; a girl of that age is valued at three shekels of silver. A man older than sixty is valued at fifteen shekels of silver; a woman of that age is valued at ten shekels of silver. If you desire to make such a vow but cannot afford to pay the required amount, take the person to the priest. He will determine the amount for you to pay based on what you can afford. “If your vow involves giving an animal that is acceptable as an offering to the LORD, any gift to the LORD will be considered holy. You may not exchange or substitute it for another animal—neither a good animal for a bad one nor a bad animal for a good one. But if you do exchange one animal for another, then both the original animal and its substitute will be considered holy.