Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "Time will contract, knowledge will decrease, tribulations will appear, and killing (harj) will increase greatly." The people asked: "O Messenger of Allah (peace and blessings be upon him)! What is meant by harj?" The Prophet Muhammad (peace and blessings be upon him) replied: "Killing."