Ibn Kathīr, may Allah have mercy on him, said: “The treasure mentioned in this context is the treasure of the Kaaba. Three sons of caliphs will fight there to seize it, until the end times arrive and the Mahdi emerges. He will appear from the lands of the East, not from the cellar in Samarra, as the ignorant Rāfidis claim—that he is presently there and that they await his emergence at the end of time. This is a form of delirium, an ample share of forsakenness, and a grievous delusion from Satan, for there is neither evidence nor proof for it—not from the Book, the sunnah, sound reason, or considered judgment.”
He also said: “He will be supported by people from the East who will aid him, establish his rule, and strengthen its foundations. Their banners will likewise be black, an emblem bearing dignity, for the banner of the Messenger of Allah, may Allah bless him and grant him peace, was black and was called al-ʿUqāb (the Eagle).”
He went on to say: “The point is that the praised and promised Mahdi, whose appearance is foretold at the end of time, will first appear and emerge from the direction of the East, and allegiance will be pledged to him at the Kaaba, as indicated by some hadiths.” (1)