Deuteronomy 18:17-21

And the Lord said to me, ‘They have spoken well.

I will raise up for them a prophet from among their countrymen like you, and I will put My words in his mouth, and he shall speak to them everything that I command him.

And it shall come about that whoever does not listen to My words which he speaks in My name, I Myself will require it of him.

But the prophet who speaks a word presumptuously in My name, a word which I have not commanded him to speak, or which he speaks in the name of other gods, that prophet shall die.’

And if you say in your heart, ‘How will we recognize the word which the Lord has not spoken?’