Sahih Muslim
The Book Pertaining to the Turmoil and Portents of the Last Hour (Kitab Al-Fitan wa Ashrat As-Saah)
Book Number: 041 / Hadith Number: 6968
This hadith has been transmitted on the authority of Umm Salama that Allah's Messenger (may peace be upon him) said to 'Ammar: A group of rebels would kill you.