Deuteronomy 18:19-21

Amplified Bible

¹⁹ It shall come about that whoever will not listen to My words which he shall speak in My name, I Myself will require it of him [and there will be consequences]. ²⁰ But the prophet who presumes to speak a word in My name which I have not commanded him to speak, or which he speaks in the name of other gods—that prophet shall die.’ ²¹ If you say in your heart, ‘How will we know and recognize the word which the Lord has not spoken?’