(11) باب ثَوَابِ الْعَبْدِ وَأَجْرِهِ إِذَا نَصَحَ لِسَيِّدِهِ وَأَحْسَنَ عِبَادَةَ اللَّهِ
Ibn Umar reported Allah's Messenger (ﷺ) as saying:
When a slave looks to the welfare of his master and worships Allah well, he has two rewards for him.
Reference: Sahih Muslim 1664 a
In-book reference: Book 27, Hadith 66
USC-MSA web (English) reference(deprecated numbering scheme): Book 15, Hadith 4097