Kitab al-Fitan · Nu'aym ibn Hammad

If a village called Harasta is eclipsed, and two caliphs from the Abbasids are deposed, and the Abbasids disagree among themselves until twelve banners and twelve banners are raised among them, then turmoil will prevail over them in the abode of their kingship, and they will gather in it, and at that time the Hereafter, and the Gihon will cross, and in it they will gather, and at that time their king will fall, and the barbarians will emerge from the Levant.

The last sign of the demise of the rule of the Banu Abbas are three kings among them who succeed one another. Their names are the names of the prophets. They will not exceed them after these kings. The duration of the Banu Abbas among these three kings is forty years. If you see differences among them, and a group of Banu Hashim gathered between the two rivers, and the mandate of a man from the Banu Abbas towards the west, and the clashing of the black flags, and zeroing in the navel of the Levant, and the killing of the governor of Egypt, and the prevention of its tax, then it is a sign of the interruption of their period.