A slave who worships his Lord and he is also honest and faithful to his master Sahih al-Bukhari 2547
Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، أَخْبَرَنَا سُفْيَانُ، عَنْ صَالِحٍ، عَنِ الشَّعْبِيِّ، عَنْ أَبِي بُرْدَةَ، عَنْ أَبِي مُوسَى الأَشْعَرِيِّ ـ رضى الله عنه ـ قَالَ النَّبِيُّ صلى الله عليه وسلم "أَيُّمَا رَجُلٍ كَانَتْ لَهُ جَارِيَةٌ فَأَدَّبَهَا فَأَحْسَنَ تَأْدِيبَهَا، وَأَعْتَقَهَا وَتَزَوَّجَهَا، فَلَهُ أَجْرَانِ، وَأَيُّمَا عَبْدٍ أَدَّى حَقَّ اللَّهِ وَحَقَّ مَوَالِيهِ، فَلَهُ أَجْرَانِ "
Translation
Narrated Abu Musa Al-Ash`ari
The Prophet (ﷺ) said, "He who has a slave-girl and teaches her good manners and improves her education and then manumits and marries her, will get a double reward; and any slave who observes Allah's right and his master's right will get a double reward."