Deuteronomy 13:6-11

False Prophets in the Family

13:6 Suppose your own full brother, your son, your daughter, your beloved wife, or your closest friend should seduce you secretly and encourage you to go and serve other gods that neither you nor your ancestors have previously known, 13:7 the gods of the surrounding people (whether near you or far from you, from one end of the earth to the other). 13:8 You must not give in to him or even listen to him; do not feel sympathy for him or spare him or cover up for him. 13:9 Instead, you must kill him without fail! Your own hand must be the first to strike him, and then the hands of the whole community. 13:10 You must stone him to death because he tried to entice you away from the Lord your God, who delivered you from the land of Egypt, that place of slavery. 13:11 Thus all Israel will hear and be afraid; no longer will they continue to do evil like this among you.

Deuteronomy 18:20-22

18:20 “But if any prophet presumes to speak anything in my name that I have not authorized him to speak, or speaks in the name of other gods, that prophet must die. 18:21 Now if you say to yourselves, ‘How can we tell that a message is not from the Lord?’ – 18:22 whenever a prophet speaks in my name and the prediction is not fulfilled, then I have not spoken it; the prophet has presumed to speak it, so you need not fear him.”