Jami` at-Tirmidhi 1922
جامع الترمذي#1922Sahihحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ إِسْمَاعِيلَ بْنِ أَبِي خَالِدٍ، حَدَّثَنَا قَيْسُ بْنُ أَبِي حَازِمٍ، حَدَّثَنَا جَرِيرُ بْنُ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ لاَ يَرْحَمُ النَّاسَ لاَ يَرْحَمُهُ اللَّهُ " . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ . قَالَ وَفِي الْبَابِ عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ وَأَبِي سَعِيدٍ وَابْنِ عُمَرَ وَأَبِي هُرَيْرَةَ وَعَبْدِ اللَّهِ بْنِ عَمْرٍو .
Jarir bin Abdullah narrated that the Messenger of Allah said:"Whoever does not show mercy to the people, Allah will not show mercy to him
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: 27:28