Exodus 22:18 - Albert Barnes' Notes on the Bible

Thou shalt not suffer a witch to live - See the marginal references. and Leviticus 20:27. The witch is here named to represent the class. This is the earliest denunciation of witchcraft in the law. In every form of witchcraft there is an appeal to a power not acting in subordination to the divine law. From all such notions and tendencies true worship is designed to deliver us. The practice of witchcraft was therefore an act of rebellion against Yahweh, and, as such, was a capital crime. The passages bearing on the subject in the Prophets, as well as those in the law, carry a lesson for all ages. Isaiah 8:19; Isaiah 19:3; Isaiah 44:25; Isaiah 47:12-13; Micah 5:12, etc.