Leviticus 27:8-10

Tree of Life Version

⁸ But if he is poorer than your valuation, then he is to be set before the kohen and the kohen will set a value for him, in keeping with what the one who made the vow can afford.

⁹ “Now if it is an animal that may be brought as an offering to Adonai, anything that one gives to Adonai will be holy. ¹⁰ He is not to replace it or exchange it, either good for bad, or bad for good. But if he does exchanges one animal for another, then both it and the one for which it is exchanged will become holy.