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The Mahdis ascendancy to power is said to be preceded by an army from the east who will be carrying black flags or banners of war. Sheikh Kabbani states:
Hadith indicate that black flags coming from the area of Khorasan will signify the appearance of the Mahdi is nigh. Khorasan is in todays Iran, and some scholars have said that this hadith means when the black flags appear from Central Asia, i.e. in the direction of Khorasan, then the appearance of the Mahdi is imminent. 17
Another tradition states that:
The Messenger of Allah said: The black banners will come from the East and their hearts will be as firm as iron. Whoever hears of them should join them and give allegiance, even if it means crawling across snow. 18
In Islam there are two flags. One is white and one is black. Written across both flags in Arabic are the words, There is no God but Allah and Muhammad is his Messenger. The white flag is called Al-Liwaa and serves as the sign for the leader of the Muslim army and is the flag of the Islamic State. The black flag is called Ar-Raya and is used by the Muslim army. It is also called the flag of jihad, and is carried into battle. One flag is governmental and the other is a military flag. 19 When Muhammad returned to his home city of Mecca after being exiled for eight years, he returned as a conqueror. With him were ten thousand Muslim soldiers. They carried with them black flags. On the flags was one word written in Arabic: punishment. 20
I was once talking to a group of young Muslim men and asking them some questions. I asked them if the obvious superior militaries of America and Israel compared to the militaries of any Islamic nations were a source of difficulty for many Muslims. One of these men then became very angry at my question and snapped out, You Americans and Zionists better get ready, because the black flags are coming! At the time, I had no idea what he was talking about. Later I learned the meaning.