Sahih al-Bukhari 2552
Sahih al-Bukhari · Book 49: Manumission of Slaves · It is dislike to look down upon a slave
Narrated Abu Huraira:
حَدَّثَنَا مُحَمَّدٌ ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ ، أَخْبَرَنَا مَعْمَرٌ ، عَنْ هَمَّامِ بْنِ مُنَبِّهٍ ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ يُحَدِّثُ عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " لاَ يَقُلْ أَحَدُكُمْ أَطْعِمْ رَبَّكَ، وَضِّئْ رَبَّكَ، اسْقِ رَبَّكَ. وَلْيَقُلْ سَيِّدِي مَوْلاَىَ. وَلاَ يَقُلْ أَحَدُكُمْ عَبْدِي أَمَتِي. وَلْيَقُلْ فَتَاىَ وَفَتَاتِي وَغُلاَمِي " .
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).