Deuteronomy 18:22
22 owhen a prophet speaks in the name of the Lord, if the word does not come to pass or come true, that is a word that the Lord has not spoken; nthe prophet has spoken it presumptuously. You need not be afraid of him.
Jeremiah 28:9
9 wAs for the prophet who prophesies peace, when the word of that prophet comes to pass, then it will be known that the Lord has truly sent the prophet.”