Sunan Abi Dawud 4686
سنن أبي داود#4686Sahihحَدَّثَنَا أَبُو الْوَلِيدِ الطَّيَالِسِيُّ، حَدَّثَنَا شُعْبَةُ، قَالَ وَاقِدُ بْنُ عَبْدِ اللَّهِ أَخْبَرَنِي عَنْ أَبِيهِ، أَنَّهُ سَمِعَ ابْنَ عُمَرَ، يُحَدِّثُ عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " لاَ تَرْجِعُوا بَعْدِي كُفَّارًا يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ " .
Ibn ‘Umar reported the Prophet (May peace be upon him) as saying :Do not turn unbelievers after me ; one of you may strike the neck of the other
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:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Zubair Ali ZaiSahih Bukhari (6868) Sahih Muslim (66)
In-book reference: 42:91