Chapter 3: Knowledge
Narrated Abu Burda' s father: Allah' s Messenger (ﷺ) said "Three persons will have a double reward: 1. A Person from the people of the scriptures who believed in his
prophet (Jesus or Moses) and then believed in the Prophet (ﷺ) Muhammad (i. e. has embraced Islam). 2. A slave who discharges his duties to Allah and his master. 3. A master of a woman-slave who teaches her good manners and educates
her in the best possible way (the religion) and manumits her and then
marries her."
Sahih al-Bukhari 97