Zakharia 13:2-3

13:2 And also on that day,” says the Lord who rules over all, “I will remove ¹  the names of the idols from the land and they will never again be remembered. Moreover, I will remove the prophets and the unclean spirit from the land. 13:3 Then, if anyone prophesies in spite of this, his father and mother to whom he was born will say to him, ‘You cannot live, for you lie in the name of the Lord.’ Then his father and mother to whom he was born will run him through with a sword when he prophesies. ² 

[13:2]  ¹ tn Heb “cut off” (so NRSV); NAB “destroy”; NIV “banish.”

[13:3]  ² sn Death (in this case being run…through with a sword) was the penalty required in the OT for prophesying falsely (Deut 13:6-11; 18:20-22).