Narrated `Abdullah
The Prophet (ﷺ) said, "If a slave serves his Saiyid (i.e. master) sincerely and worships his Lord (Allah) perfectly, he will get a double reward."
Narrated Abu Musa
The Prophet (ﷺ) said, "The Mamluk (slave) who worships his Lord in a perfect manner, and is dutiful, sincere and obedient to his Saiyid (master), will get a double reward."
Narrated Abu Huraira
The Prophet (ﷺ) said, "You should not say, 'Feed your lord (Rabbaka), help your lord in performing ablution, or give water to your lord, but should say, 'my master (e.g. Feed your master instead of lord etc.) (Saiyidi), or my guardian (Maulai), and one should not say, my slave (Abdi), or my girl-slave (Amati), but should say, my lad (Fatai), my lass (Fatati), and 'my boy (Ghulami).
Narrated Ibn `Umar
The Prophet (ﷺ) said, "If one manumits his share of a common slave (Abd), and he has money sufficient to free the remaining portion of the price of the slave (justly estimated), then he should free the slave completely by paying the rest of his price; otherwise the slave is freed partly. "
Narrated `Abdullah
Allah's Messenger (ﷺ) said, "Everyone of you is a guardian and is responsible for his charges. The ruler who has authority over people, is a guardian and is responsible for them, a man is a guardian of his family and is responsible for them; a woman is a guardian of her husband's house and children and is responsible for them; a slave ('Abu) is a guardian of his master's property and is responsible for it; so all of you are guardians and are responsible for your charges."
Narrated Abu Huraira and Zaid bin Khalid
The Prophet (ﷺ) said, "If a slave-girl (Ama) commits illegal sexual intercourse, scourge her; if she does it again, scourge her again; if she repeats it, scourge her again." The narrator added that on the third or the fourth offense, the Prophet (ﷺ) said, "Sell her even for a hair rope."