Arabic (Original)
وَحَدَّثَنَا عَمْرُو بْنُ عَلِيٍّ قَالَ نا الْمُعْتَمِرُ بْنُ سُلَيْمَانَ عَنْ أَبِيهِ عَنْ أَبِي عَمْرٍو الشَّيْبَانِيِّ عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ
English Translation
And Amr ibn Ali narrated to us, he said: al-Mu'tamir ibn Sulayman narrated to us, from his father, from Abu Amr al-Shaybani, from Abdullah ibn Mas'ud, that the Prophet (blessings and peace of Allah be upon him) said: «Reviling a Muslim is wickedness, and fighting him is disbelief.»