Mukhtasar Muslim

Abu Huraira (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings of Allah be upon him) said: By Him in Whose hand is my soul! The world will not end until a time comes upon the people when the killer will not know why he is killing, and the one being killed will not know why he is being killed. The people asked: How will this happen? He (peace be upon him) replied: There will be widespread killing. Both the killer and the one killed will be in Hell.