Sunan an-Nasa'i 3344
سنن النسائي#3344SahihIt was narrated that Abu Musa said:"The Messenger of Allah said: 'There are three who will be given a twofold reward: A man who has a slave woman whom he disciplines and disciplines her well, and teaches and teaches her well, then he manumits her and marries her; a slave who fulfills his duty toward Allah and toward his masters; and a believer from among the People of the Book
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 26:149