Abu Dawud
General Behavior
Book Number: 036 / Hadith Number: 4957
Narated By AbuHurayrah : The Prophet (pbuh) said: None of you must say: "My slave" (abdi) and "My slave-woman" (amati), and a slave must not say: "My lord" (rabbi or rabbati). The master (of a slave) should say: "My young man" (fataya) and "My young woman" (fatati), and a slave should say "My master" (sayyidi) and "My mistress" (sayyidati), for you are all (Allah's slave and the Lord is Allah, Most High.