Deuteronomy 18:20-22

Modern English Version

²⁰ But the prophet, who presumes to speak a word in my name, which I have not commanded him to speak, or who shall speak in the name of other gods—that prophet shall die.”

²¹ And you may say in your heart, “How can we know the word which the Lord has not spoken?” ²² When a prophet speaks in the name of the Lord, if the thing does not occur or come to pass, that is the thing which the Lord has not spoken; the prophet has spoken it presumptuously. You shall not be afraid of him.