Leviticus 20:6-7, 27

And the soul that turneth unto them that have familiar spirits, and unto the wizards, to play the harlot after them, I will even set my face against that soul, and will cut him off from among his people. Sanctify yourselves therefore, and be ye holy; for I am Jehovah your God.

A man also or a woman that hath a familiar spirit, or that is a wizard, shall surely be put to death: they shall stone them with stones; their blood shall be upon them.