It was narrated that 'Arfajah bin Shuraih said:"The Prophet [SAW] said: 'After me there will be many calamities and much evil behavior.' He raised his hands (and said): 'Whomever you see trying to create division among the Ummah of Muhammad [SAW] when they are all united, kill him, no matter who he is among the people

English translation · Sunan an-Nasa'i