Many of the great Sufis were called "Qutb al-Aqtab" (Pole of Poles) and "al-Qutb al-Rabbani" (the Divine Pole), and so on. They also called him "Majma' al-Bahrain" (the Confluence of the Two Seas) because the sea of necessity and possibility converges in him, and the divine names and cosmic realities converge in him, etc. Thus, there is much proximity between the teachings of Sufism and the teachings of the Shi'a in this regard, as well as between the teachings of Sufism and the teachings of the Mahdist movement. Ibn Khaldun devoted a valuable chapter to the Mahdi and the Mahdist movement, in which he mentioned the hadiths that have been narrated about the Mahdi, such as what Jabir narrated, saying: The Messenger of Allah (peace be upon him) said: "Whoever denies the Mahdi has disbelieved, and whoever denies the Antichrist has disbelieved." And like what Al-Tirmidhi narrated from the Prophet (peace be upon him): "If only one day remained of the world, Allah would prolong that day until Allah sends a man from me whose name is like my name, and his father's name is like my father's name." And like a hadith from Ali from the Prophet, who said: "If only one day remained of time, Allah would send a man from my household, who would fill it with justice as it was filled with injustice." And like what Al-Hakim narrated from Umm Salama, who said: "I heard the Messenger of Allah (peace be upon him) mention the Mahdi and say: He is the truth, and he is from the children of Fatima." And from Abu Saeed Al-Khudri, who said: "The Messenger of Allah (peace be upon him) said:"