Jami` at-Tirmidhi 1985
جامع الترمذي#1985Sahihحَدَّثَنَا ابْنُ أَبِي عُمَرَ، حَدَّثَنَا سُفْيَانُ، عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " نِعِمَّا لأَحَدِهِمْ أَنْ يُطِيعَ رَبَّهُ وَيُؤَدِّيَ حَقَّ سَيِّدِهِ " يَعْنِي الْمَمْلُوكَ . وَقَالَ كَعْبٌ صَدَقَ اللَّهُ وَرَسُولُهُ . وَفِي الْبَابِ عَنْ أَبِي مُوسَى وَابْنِ عُمَرَ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
Abu Hurairah narrated that the Messenger of Allah said:"How wonderful it is for one of them that he obeys Allah and fulfills the rights of his master." Meaning the slave. And Ka'b said: "Allah and His Messenger spoke the truth
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 27:91