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Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
ahmad:21571 – ʿAbd al-Ṣamad from my father > Ḥusayn > Ibn Buraydah > Yaḥyá b. Yaʿmar > Abū al-Aswad > Abū Dhar

That he heard the Prophet ﷺ saying, "If somebody accuses another of Fusuq (by calling him 'Fasiq' i.e. a wicked person) or accuses him of Kufr, such an accusation will revert to him (i.e. the accuser) if his companion (the accused) is innocent." (Using translation from Bukhārī 6045)  

أحمد:٢١٥٧١ – حَدَّثَنَا عَبْدُ الصَّمَدِ حَدَّثَنِي أَبِي حَدَّثَنِي حُسَيْنٌ قَالَ قَالَ ابْنُ بُرَيْدَةَ حَدَّثَنِي يَحْيَى بْنُ يَعْمَرَ أَنَّ أَبَا الْأَسْوَدِ حَدَّثَهُ عَنْ أَبِي ذَرٍّ

أَنَّهُ سَمِعَ رَسُولَ اللهِ ﷺ يَقُولُ لَا يَرْمِي رَجُلٌرَجُلًا بِالْفِسْقِ وَلَا يَرْمِيهِ بِالْكُفْرِ إِلَّا ارْتَدَّتْ عَلَيْهِ إِنْ لَمْ يَكُنْ صَاحِبُهُ كَذَلِكَ  

See similar narrations below:

Collected by Bukhārī
bukhari:6045 – Abū Maʿmar > ʿAbd al-Wārith > al-Ḥusayn > ʿAbdullāh b. Buraydah > Yaḥyá b. Yaʿmar > Abū al-Aswad al-Dīlī > Abū Dhar

That he heard the Prophet ﷺ saying, "If somebody accuses another of Fusuq (by calling him 'Fasiq' i.e. a wicked person) or accuses him of Kufr, such an accusation will revert to him (i.e. the accuser) if his companion (the accused) is innocent."  

البخاري:٦٠٤٥ – حَدَّثَنَا أَبُو مَعْمَرٍ حَدَّثَنَا عَبْدُ الْوَارِثِ عَنِ الْحُسَيْنِ عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ حَدَّثَنِي يَحْيَى بْنُ يَعْمَرَ أَنَّ أَبَا الأَسْوَدِ الدِّيلِيَّ حَدَّثَهُ عَنْ أَبِي ذَرٍّ ؓ

أَنَّهُ سَمِعَ النَّبِيَّ ﷺ يَقُولُ لاَ يَرْمِي رَجُلٌ رَجُلاً بِالْفُسُوقِ وَلاَ يَرْمِيهِ بِالْكُفْرِ إِلاَّ ارْتَدَّتْ عَلَيْهِ إِنْ لَمْ يَكُنْ صَاحِبُهُ كَذَلِكَ