Deuteronomy 18:21-22

English Standard Version

²¹ And if you say in your heart, ‘How may we know the word that the Lord has not spoken?’— ^22 (A)when 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; ^(B)the prophet has spoken it presumptuously. You need not be afraid of him.