Jami` at-Tirmidhi 3902
جامع الترمذي#3902Sahihحَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ، قَالَ حَدَّثَنَا هُشَيْمٌ، قَالَ أَخْبَرَنَا عَلِيُّ بْنُ زَيْدِ بْنِ جُدْعَانَ، قَالَ حَدَّثَنَا النَّضْرُ بْنُ أَنَسٍ، عَنْ زَيْدِ بْنِ أَرْقَمَ، أَنَّهُ كَتَبَ إِلَى أَنَسِ بْنِ مَالِكٍ يُعَزِّيهِ فِيمَنْ أُصِيبَ مِنْ أَهْلِهِ وَبَنِي عَمِّهِ يَوْمَ الْحَرَّةِ فَكَتَبَ إِلَيْهِ إِنِّي أُبَشِّرُكَ بِبُشْرَى مِنَ اللَّهِ إِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " اللَّهُمَّ اغْفِرْ لِلأَنْصَارِ وَلِذَرَارِيِّ الأَنْصَارِ وَلِذَرَارِيِّ ذَرَارِيِّهِمْ " . هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ . وَقَدْ رَوَاهُ قَتَادَةُ عَنِ النَّضْرِ بْنِ أَنَسٍ، عَنْ زَيْدِ بْنِ أَرْقَمَ، .
Zaid bin Arqam wrote to Anas bin Malik, comforting him over those of his family and children of his paternal uncle who suffered on the day of Al-Harrah. So he wrote to him:"I give you glad tidings of good news from Allah. I heard the Messenger of Allah (ﷺ) say: 'O Allah forgive the Ansar and the children of the Ansar, and the children of their children
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: 49:302