It is narrated from Sayyiduna Abu Musa Ash'ari (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: "Whoever teaches his slave-girl and teaches her well, and gives her good moral training and trains her well, then sets her free and marries her, he will receive a double reward. (Similarly, there are two rewards) for the slave who fulfills the right of Allah Almighty and also the right of his master, and for the person from the People of the Book who first believed in the Shari'ah brought by Jesus (peace be upon him) and then believed in the Shari'ah brought by Muhammad (peace and blessings be upon him), for him also there are two rewards."
Hadith Referenceالفتح الربانی / كتاب الإيمان و الإسلام / 116
Hadith Gradingمحدثین:صحیح
Hadith Takhrij«أخرجه البخاري: 97، 3011، 3446، 5083، ومسلم: 154، (انظر مسند أحمد ترقيم الرسالة: 19532 ترقیم بيت الأفكار الدولية: 19761»
Brief Explanation
Benefits: … Since those among the People of the Book who believe in you (sallallahu alayhi wa sallam) have faith in two prophets one after the other, therefore they receive a double reward.