Wedlock, Marriage (Nikaah)
Bukhari :: Book 7 :: Volume 62 :: Hadith 148
Narrated 'Aisha:
Allah's Apostle said, "O followers of Muhammad! There is none, who has a greater sense of Ghira (self-respect) than Allah, so He has forbidden that His slave commits illegal sexual intercourse or His slave girl commits illegal sexual intercourse. O followers of Muhammad! If you but knew what I know, you would laugh less and weep more!"