The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fada'il)
Muslim :: Book 30 : Hadith 5655
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: I shall be pre-eminent arriongst the descendants of Adam on the Day of Resurrection and I will be the first intercessor and the first whose intercession will be accepted (by Allah).