فضائل التوحيد
Abu Mūsa al-Ash‘ari (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Three kinds of people will have a double reward: A man from the People of the Scripture (Jews or Christians) who believed in his prophet and (also) believed in Muhammad; a slave who fulfills his duties towards Allah and towards his master; and a man who owned a slave-girl, so he disciplined her well and educated her well then freed her and married her. He will receive a double reward."
عن أبي موسى الأشعري -رضي الله عنه- مرفوعاً: «ثلاثة لهم أجران: رجل من أهل الكتاب آمن بنبيه، وآمن بمحمد، والعبد المملوك إذا أدى حق الله، وحق مواليه، ورجل كانت له أمة فأدبها فأحسن تأديبها، وعلمها فأحسن تعليمها، ثم أعتقها فتزوجها؛ فله أجران».
شرح الحديث :
This Hadīth underlines the merit of three kinds of people: The People of the Book (Christians and Jews) who embraced Islam, as they are rewarded for following their prophet and following Prophet Muhammad (may Allah's peace and blessings be upon him); The slave who fulfills the rights of Allah upon him as well as the rights of his master upon him; and the man who disciplines and educates his slave-girl well then sets her free and marries her. He will receive a reward for being good to her and freeing her, and another reward for marrying her to help her guard her chastity.