The Book on Salutations and Greetings (Kitab As-Salam)
Muslim :: Book 26 : Hadith 5532
Mu'awiya b. al-Hakam as-Sulami reported: I said: Messenger of Allah, there were things we used to do in the pre-Islamic days. We used to visit Kahins, whereupon he said: Don't visit Kahins. I said: We used to take omens. He said: That is a sort of personal whim of yours, so let it not prevent you (from doing a thing).