Deuteronomy 18:20-22

New Revised Standard Version, Anglicised

²⁰ But any prophet who speaks in the name of other gods, or who presumes to speak in my name a word that I have not commanded the prophet to speak—that prophet shall die.’ ²¹ You may say to yourself, ‘How can we recognize a word that the Lord has not spoken?’ ²² If a prophet speaks in the name of the Lord but the thing does not take place or prove true, it is a word that the Lord has not spoken. The prophet has spoken it presumptuously; do not be frightened by it.