Virtues and Merits of the Prophet (pbuh) and his Companions
Bukhari :: Book 4 :: Volume 56 :: Hadith 696
Narrated Abu Huraira:
Once Allah's Apostle was asked, "Who is the most honorable amongst the people?" He said, "The most righteous (i.e. Allah-fearing) amongst you." They said, "We do not ask you about this." He said, "Then Joseph, the prophet of Allah."