Yahya related to me from Malik from Yahya ibn Said that AbuSalama ibn Abd ar-Rahman said, "I heard Abu Qatada ibn Ribiyy say thathe heard the Messenger of Allah, may Allah bless him and grant himpeace, say, 'The good dream is from Allah, and the bad dream is fromshaytan. When you see what you dislike, spit to your left side threetimes when you wake up, and seek refuge with Allah from its evil. Itwill not harm you then, Allah willing.' " Abu Salama said, "I wouldsee dreams which weighed on me more heavily than a mountain. When Iheard this hadith, I was not concerned about it."
USC-MSA web (English) reference: Book 52, Hadith 4
Arabic reference: Book 52, Hadith 1754