Leviticus 27:8-10

Living Bible

⁸ But if the person is too poor to pay this amount, he shall be brought to the priest, and the priest shall talk it over with him, and he shall pay as the priest shall decide.

⁹ “But if it is an animal that is vowed to be given to the Lord as a sacrifice, it must be given. ¹⁰ The vow may not be changed; the donor may neither change his mind about giving it to the Lord, nor substitute good for bad or bad for good; if he does, both the first and the second shall belong to the Lord!