Leviticus 27:8-10

Revised Standard Version

⁸ And if a man is too poor to pay your valuation, then he shall bring the person before the priest, and the priest shall value him; according to the ability of him who vowed the priest shall value him.

⁹ “If it is an animal such as men offer as an offering to the Lord, all of such that any man gives to the Lord is holy. ¹⁰ He shall not substitute anything for it or exchange it, a good for a bad, or a bad for a good; and if he makes any exchange of beast for beast, then both it and that for which it is exchanged shall be holy.