Musnad Abu Ya'la al-Mawsili 160:134

And with his chain of narration, that the Prophet (may Allah bless him and grant him peace) said: "Let not one of you say, 'My slave' (abdi) and 'My slave-girl' (amati), for all of you are slaves of Allah, and all of your women are slave-girls of Allah. But let him say, 'My young man' (fatay) and 'My boy' (ghulami), and 'My slave-girl' (jariyati)."