Deuteronomy 18

20 ‘Only, the prophet who presumeth to speak a word in My name — that which I have not commanded him to speak — and who speaketh in the name of other gods — even that prophet hath died.

21 ‘And when thou sayest in thy heart, How do we know the word which Jehovah hath not spoken? —

22 that which the prophet speaketh in the name of Jehovah, and the thing is not, and cometh not — it [is] the word which Jehovah hath not spoken; in presumption hath the prophet spoken it; — thou art not afraid of him.