Muwatta Imam Malik Book of General Subjects, Hadith 43

Malik related to me from Nafi from Abdullah ibn Umar that the Messenger of Allah ﷺ said, "When a slave gives good counsel to his master and worships Allah correctly, he has his reward twice over. "

حَدَّثَنِي مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " الْعَبْدُ إِذَا نَصَحَ لِسَيِّدِهِ وَأَحْسَنَ عِبَادَةَ اللَّهِ فَلَهُ أَجْرُهُ مَرَّتَيْنِ " .