Hazrat Anas (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: Among the signs of the Hour is that (religious) knowledge will be taken away and ignorance will become widespread. And wine will be drunk openly and adultery will become prevalent.

Hazrat Abu Musa (may Allah be pleased with him) narrated that the Prophet Muhammad (peace and blessings be upon him) said: On the Day of Resurrection, there will first be such days in which ignorance will descend and knowledge will be taken away, and "harj" will increase, and "harj" means killing.

Hazrat Abu Huraira (may Allah be pleased with him) narrated that the Noble Prophet (peace and blessings be upon him) said: Time will draw near, deeds will decrease, greed will be cast into the hearts, tribulations will become apparent, and there will be an abundance of "harj." The people asked: O Messenger of Allah! What is this "harj"? The Prophet (peace and blessings be upon him) replied: Killing, killing!

Abdullah bin Amr bin al-As (may Allah be pleased with him) narrated that I heard the Messenger of Allah (peace and blessings be upon him) say: "Allah will not take away knowledge by snatching it from the servants, but He will take away knowledge by causing the scholars to die. When no scholar remains, people will take ignorant ones as leaders; they will be asked questions and will give answers without knowledge. Thus, they will go astray themselves and will lead others astray as well."