Don't allow your mouth to lead you into sin. Don't protest before the messenger that this was a mistake. Why should God be angry at your voice, and destroy the work of your hands?
He shall not alter it, nor change it, a good for a bad, or a bad for a good: and if he shall at all change animal for animal, then both it and that for which it is changed shall be holy.
But if he is poorer than your valuation, then he shall be set before the Kohen, and the Kohen shall value him; according to the ability of him who vowed shall the Kohen value him.
*If anyone commits a trespass, and sins unwittingly, in the holy things of the LORD; then he shall bring his trespass offering to the LORD, a ram without blemish from the flock, according to your estimation in silver by shekels, after the shekel of the sanctuary, for a trespass offering.