Muslim narrated it (1).

In a narration by al-Bukhārī from Abd Allah ibn Masūd: “Immediately before the Hour, there will be days of harj: knowledge will disappear and ignorance will prevail.” Abū Mūsā said: “Harj means killing in the language of the Abyssinians.” (2)

Abū Mūsā—may Allah be pleased with him—also reported from the Prophet, who said: “Immediately before the Hour there will be harj.” They asked, “What is harj?” He replied, “Killing.” They said, “More than the number we kill? In a single year, we kill more than seventy thousand.” He said, “It does not mean your killing the polytheists, but rather your killing one another.” They asked, “Will we still possess our reason at that time?” He replied, “The minds of most people of that time will indeed be taken away, and a mindless rabble will be left behind. Most of them will think they are in the right, but they are not.” (3)

Abū Hurayra—may Allah be pleased with him—reported that the Messenger of Allah—peace and blessings be upon him—said: “By Him in whose hand is my soul, this world will not pass away until a day comes upon people when the killer does not know why he killed, nor the victim why he was killed.” He was asked, “How will that be?” He replied, “Harj,