Sahih al-Bukhari 2549
Sahih al-Bukhari · Book 49: Manumission of Slaves · A slave who worships his Lord and he is also honest and faithful to his master
Narrated Abu Huraira:
حَدَّثَنَا إِسْحَاقُ بْنُ نَصْرٍ ، حَدَّثَنَا أَبُو أُسَامَةَ ، عَنِ الأَعْمَشِ ، حَدَّثَنَا أَبُو صَالِحٍ ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " نِعْمَ مَا لأَحَدِهِمْ يُحْسِنُ عِبَادَةَ رَبِّهِ وَيَنْصَحُ لِسَيِّدِهِ " .
The Prophet (ﷺ) said, "Goodness and comfort are for him who worships his Lord in a perfect manner and serves his master sincerely."