Salim says: I do not remember how many times I have heard Abu Hurairah (may Allah be pleased with him) standing in the market saying: Knowledge will be taken away, tribulations will appear, and killing (harj) will increase. The companions (may Allah be pleased with them) asked: O Messenger of Allah (peace and blessings be upon him), what is meant by harj? The Prophet (peace and blessings be upon him) gestured with his hand (killing, killing).