Musnad Abu Ya'la al-Mawsili 152:182

Abu Khaythama narrated to us, Abd al-Rahman narrated to us, from Sufyan, from Abu Ishaq, from Abu al-Ahwas, from Abdullah, from the Prophet (peace and blessings of Allah be upon him), who said: "Whoever sees me in a dream has indeed seen me, for the devil does not impersonate me."