Sahih Bukhari
Sahih Bukhari Volume 003, Book 046, Hadith Number 723.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 46. Manumission Of Slaves
Narated By Abu Musa Al-Ashari : The Prophet said, "He who has a slave-girl and teaches her good manners and improves her education and then manumits and marries her, will get a double reward; and any slave who observes Allah's right and his master's right will get a double reward."