Sayyiduna Abu Musa (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "There are three persons for whom there is a double reward. One who is from the People of the Book and believes in his own prophet and in Muhammad (peace and blessings be upon him). The second is a slave who fulfills the rights of both his master and Allah. And the third is a man who has a slave-girl, trains her well, teaches her well, then sets her free and marries her; for him there is a double reward."