Leviticus 27:8-10

English Standard Version

⁸ 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.

⁹ “If the vow^[a] is an animal that may be offered as an offering to the Lord, all of it that he gives to the Lord is holy. ^10 (A)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.