Be on guard concerning all that I have told you. Make no mention of the names of other gods; they shall not be heard on your lips.
Exodus 23:13
If you hear it said, of one of the towns that the LORD your God is giving you to dwell in, that some scoundrels from among you have gone and subverted the inhabitants of their town, saying, “Come let us worship other gods”—whom you have not experienced— you shall investigate and inquire and interrogate thoroughly. If it is true, the fact is established—that abhorrent thing was perpetrated in your midst— put the inhabitants of that town to the sword and put its cattle to the sword. Doom it and all that is in it to destruction: gather all its spoil into the open square, and burn the town and all its spoil as a holocaust to the LORD your God. And it shall remain an everlasting ruin, never to be rebuilt.
Deuteronomy 13:13-17