(28) باب بَيَانِ قَوْلِ النَّبِيِّ صلى الله عليه وسلم " سِبَابُ الْمُسْلِمِ فُسُوقٌ وَقِتَالُهُ كُفْرٌ "
It is narrated on the authority of 'Abdullah b. Mas'ud that the Messenger of Allah (may peace and blessings be upon him) observed:
Abusing a Muslim is an outrage and fighting against him is unbelief. Zubaid said: I asked Abu Wa'il: Did you hear it from Abdullah narrating if from the Messenger of Allah (may peace and blessings be upon him)? He replied: Yes. But there is mention of the talk between Zubaid and Abu Wa'il in the hadith narrated by Shu'ba. (RU)
Reference (RU): Sahih Muslim 64 a (RU)
In-book reference (RU): Book 1, Hadith 127 (RU)
USC-MSA web (English) reference(deprecated numbering scheme): Book 1, Hadith 122 (RU)