Sahih Muslim Book 27, Hadith Number 5591.
Chapter : The proper use of the words: Bondman, Slave-girl, Al-Maula and As-Sayyid.
Abu Huraira reported Allah’s Messenger (may peace be upon him) as saying: None of you should say: My bondman and my slave-girl, for all of you are the bondmen of Allah, and all your women are the slave-girls of Allah; but say: My servant, my girl, and my young man and my young girl.