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. "
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ الْعَبْدُ إِذَا نَصَحَ لِسَيِّدِهِ وَأَحْسَنَ عِبَادَةَ اللَّهِ فَلَهُ أَجْرُهُ مَرَّتَيْنِ