Leviticus 27:9-15

“If the vow is an animal that may be offered as an offering to the LORD, all of it that he gives to the LORD is holy. He shall not exchange it or make a substitute for it, good for bad, or bad for good; and if he does in fact substitute one animal for another, then both it and the substitute shall be holy. And if it is any unclean animal that may not be offered as an offering to the LORD, then he shall stand the animal before the priest, and the priest shall value it as either good or bad; as the priest values it, so it shall be. But if he wishes to redeem it, he shall add a fifth to the valuation. “When a man dedicates his house as a holy gift to the LORD, the priest shall value it as either good or bad; as the priest values it, so it shall stand. And if the donor wishes to redeem his house, he shall add a fifth to the valuation price, and it shall be his.