Abu Wa'il says that I was once sitting with Sayyiduna Ibn Mas'ud and Sayyiduna Abu Musa Ash'ari (may Allah be pleased with them). Both of these noble companions said that the Messenger of Allah (peace and blessings be upon him) said: "Near the Day of Judgment, ignorance will descend, knowledge will be taken away, and 'harj' will become widespread." We asked about the meaning of 'harj', so he said: "Killing."