Hadith 13:98
Usama b. Sharik reported God’s Messenger as saying, “Cut off the head of any man who goes out and causes division among my people.” Nasa’i transmitted it.
عَن أُسَامَةَ بْنِ شَرِيكٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَيُّمَا رَجُلٍ خَرَجَ يُفَرِّقُ بَيْنَ أُمَّتِي فَاضْرِبُوا عُنُقَهُ» . رَوَاهُ النَّسَائِيُّ
Original Reference: Mishkat al-Masabih 3552