Sunan Abi Dawud, Hadith 5150 ⓘ
‘Abd Allah b. ‘Umar reported the Messenger of Allah (May peace be upon him) as saying: when a slave acts sincerely towards his master and worship Allah well, he will have a double reward.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ الْعَبْدَ إِذَا نَصَحَ لِسَيِّدِهِ وَأَحْسَنَ عِبَادَةَ اللَّهِ فَلَهُ أَجْرُهُ مَرَّتَيْنِ " .
also referenced under: Hadith 5169 (DarusSalam) & Book 41, Hadith 5148 (USC-MSA)