The Book of Fighting [The Prohibition of Bloodshed]
37/29. Chapter:
The Prohibition of Killing
Sunan an-Nasai
أَخْبَرَنَا عَمْرُو بْنُ زُرَارَةَ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، عَنْ أَيُّوبَ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي بَكْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ تَرْجِعُوا بَعْدِي ضُلاَّلاً يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ " .
It was narrated from Abu Bakrah that: The Prophet [SAW] said: "Do not revert to misguidance after I am gone, striking the necks of one another (killing one another)."
Reference : Sunan an-Nasa'i 4130In-book reference : Book 37, Hadith 165English translation : Vol. 5, Book 37, Hadith 4135