Isaiah 8:19-20

19They will say to you, ‘Go to the people who speak to the spirits of dead people. Go to the magicians who speak magic words. They will tell you what you should do. People should ask their gods and spirits to give them messages. People who are alive should ask the spirits of dead people to help them.’

20When they say that to you, remember my teaching. Tell them what I have said will happen. People who talk like that are completely in the dark. There is no truth in what they say.