Sahih Muslim | Book 20 | Chapter 14
Narrated by It has been narrated on the authority of 'Arfaja who
It has been narrated on the authority of 'Arfaja who said: I have heard the Messenger of Allah (may peace be upon him) say: Different evils will make their appearance in the near future. Anyone who tries to disrupt the affairs of this Umma while they are united you should strike him with the sword whoever he be. (If remonstrance does not prevail with him and he does not desist from his disruptive activities, he is to be killed.)
In another version of the tradition narrated on the same authority through a different chains of transmitters we have the words: "Kill him.
Narrated by 'Arfaja
It has been narrated (through a still different chain of transmitters) on the same authority (i.e. 'Arfaja) who said similarly-but adding: "Kill all of them." I heard the Messenger of Allah (may peace be upon him) say: When you are holding to one single man as your leader, you should kill who seeks to undermine your solidarity or disrupt your unity.