Sahih Muslim 1738
صحيح مسلم#1738Sahihحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَعُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالاَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، حَدَّثَنَا شُعْبَةُ، عَنْ خُلَيْدٍ، عَنْ أَبِي نَضْرَةَ، عَنْ أَبِي سَعِيدٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لِكُلِّ غَادِرٍ لِوَاءٌ عِنْدَ اسْتِهِ يَوْمَ الْقِيَامَةِ " .
It is narrated on the authority of Abu Sa'id that the Messenger of Allah (ﷺ) said:On the Day of Judgment there will be a flag fixed behind the buttocks of every person guilty of the breach of faith
Scholarly Authentication
The label above is the grade most of these scholars gave, each scholar counted once — 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. When they judged only its chain of narrators (“Isnaad”), the label says “Sound chain”. Each scholar's own wording:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
Sahih Muslim 1738 is the standard (Abd al-Baqi) number; this narration is #4537 in the MuslimGPT index.
In-book reference: 32:18