Sunan an-Nasa'i 4130
سنن النسائي#4130Sahihأَخْبَرَنَا عَمْرُو بْنُ زُرَارَةَ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، عَنْ أَيُّوبَ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي بَكْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ تَرْجِعُوا بَعْدِي ضُلاَّلاً يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ " .
It was narrated from Abu Bakrah that:The Prophet [SAW] said: "Do not revert to misguidance after I am gone, striking the necks of one another (killing one another)
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:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 37:165