Sunan Abi Dawud 4687
سنن أبي داود#4687Sahihحَدَّثَنَا عُثْمَانُ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا جَرِيرٌ، عَنْ فُضَيْلِ بْنِ غَزْوَانَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَيُّمَا رَجُلٍ مُسْلِمٍ أَكْفَرَ رَجُلاً مُسْلِمًا فَإِنْ كَانَ كَافِرًا وَإِلاَّ كَانَ هُوَ الْكَافِرَ " .
Ibn ‘Umar reported the Messenger of Allah (May peace be upon him) as saying :If any believing man calls another believing man an unbeliever, if he is actually an infidel, it is all right ; if not, he will become an infidel
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: 42:92