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: 6966
Abu Sa'id Khudri reported: One who Is better than I informed me, that Allah's Messenger (may peace be upon him) said to 'Ammar as he was digging the ditch (on the ocasion of the Battle of the Ditch) wiping over his head: O son of Summayya you will be involved in trouble and a group of the rebels would kill you.