Musnad Abu Ya'la al-Mawsili 117:11

Ibrahim ibn al-Hajjaj al-Sami narrated to us, Abd al-Aziz ibn al-Mukhtar narrated to us, Thabit al-Bunani narrated to us, Anas narrated, he said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever sees me in a dream has indeed seen me, for the devil does not impersonate me. And the dream of the believer is one part of forty-six parts of prophethood."