It is narrated from Abdullah bin Mas'ud that we were with the Noble Prophet (peace and blessings be upon him) when some young men from Banu Hashim appeared before us. When the Noble Prophet (peace and blessings be upon him) saw them, tears came to his eyes and his color changed. I said, "O Messenger of Allah (peace and blessings be upon him), we are seeing something on your face which we do not like." The Noble Prophet (peace and blessings be upon him) said, "Allah Almighty has preferred the Hereafter over this world for my Ahl al-Bayt. After me, my Ahl al-Bayt will face trials, division, and exile. Until a people come from the east with black flags; they will demand the truth but it will not be given to them. Then they will fight and will be victorious. Then their demand will be accepted but they will not accept it until the matter of caliphate is handed over to a man from my Ahl al-Bayt. Then he will fill the earth with justice as those before him had filled it with oppression and injustice. If any of you finds this, he should go to them even if he has to crawl over snow."