Leviticus 27:10-12

Amplified Bible

¹⁰ He shall not replace it or exchange it, a good for a bad, or a bad for a good; but if he does exchange an animal for an animal, then both the original offering and its substitute shall be holy. ¹¹ If it is any unclean animal of the kind which men do not present as an offering to the Lord, then he shall bring the animal before the priest, ¹² and the priest shall value it as either good or bad; it shall be as you, the priest, value it.