Jami` at-Tirmidhi 3761
جامع الترمذي#3761Sahihحَدَّثَنَا أَحْمَدُ بْنُ إِبْرَاهِيمَ الدَّوْرَقِيُّ، قَالَ حَدَّثَنَا شَبَابَةُ، قَالَ حَدَّثَنَا وَرْقَاءُ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " الْعَبَّاسُ عَمُّ رَسُولِ اللَّهِ وَإِنَّ عَمَّ الرَّجُلِ صِنْوُ أَبِيهِ أَوْ مِنْ صِنْوِ أَبِيهِ " . هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ لاَ نَعْرِفُهُ مِنْ حَدِيثِ أَبِي الزِّنَادِ إِلاَّ مِنْ هَذَا الْوَجْهِ .
Narrated Abu Hurairah:that the Prophet (ﷺ) said: "Al-'Abbas is the uncle of the Messenger of Allah (ﷺ), and indeed, the uncle of a man is the Sinw of his father or from the Sinw of his father
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: 49:160