The Prophet Mohammed ﷺ said that, if anyone visited a fortune-teller and asked him about a matter of the unseen – about which, in reality, none possesses knowledge except Allah – and believed in what fortune teller said, Allah will not accept his prayers, nor reward them for forty days – and this is a punishment for the major sin which he has committed.
Some people asked to Prophet Mohammed ﷺ about the fore tellers. He said. -They are nothing. ” They said, O Allah’s Apostle (Sal-allahu-alleihi-wasallam)! Sometimes they tell us of a thing which turns out to be true.”
Prophet Mohammed ﷺ said, “A Jinn snatches that true word and pours it into the ear of his friend (the fore teller) (as one puts something into a bottle). The fore teller then mixes with that word one hundred lies.”
Narrated by Ayesha (Radi Allah Ta’lah Anha); Sahih Bukhari transmitted it. Vol 7:#657 of Sahih Bukhari.