Believed to appear in the end-times, and that Jesus, who is also to appear in the end-times, will be a follower of the Mahdi, and prays behind him. Some, however, believe that Jesus and the Mahdi are the same person. All proof texts are based on hadiths. The Mahdi is believed to be a member of his household (Ahlul-Bayt), from his daughter Fatima. Shi'ites claimed that he is the son of Imam Hasan al-Askari, while the Sunnis believed that it is someone else. The Shi'ites believed that the Mahdi is alive and hidden, and awaits the proper time to appear.
* The Prophet said: "Even if the entire duration of the world's existence has already been exhausted and only one day is left before Doomsday (Day of judgment), Allah will expand that day to such a length of time, as to accommodate the kingdom of a person out of my Ahlul-Bayt who will be called by my name. He will then fill out the earth with peace and justice as it will have been full of injustice and tyranny before then." (ref: Sahih Tirmidhi, v2, p.86, v9, pp. 74-75 Sunan Abi Dawud, v2, p.7 Musnad Ahmad Ibn Hanbal, v1, p.376 & v3, p.63 Mustadrak al-Sahihain, by al-Hakim, v4, p.557 Al-Majma', by Tabarani, p.217 Tahdhib al-Thabit, by Ibn Hajar al-Asqalani, v9, p.144 Sawaiq al-Muhraqa, Ibn Hajar al-Haythami, p.167 Fathul Bari, by Ibn Hajar al-Asqalani, v7, p.305 al-Tathkirah, by al-Qurtubi, p.617 al-Hawi, by al-Suyuti, v2, pp.165-166 Sharh al-Mawahib al-Ladunniyyah, by al-Zurqani, v5, p.348 Fathul Mughith, by al-Sakhawi, v3, p.41 al-Hafidh Abul-Hasan Muhammad Ibn al-Husayn al-Sijistani al-Aburi al-Shafi'i (d. 363/974) who said the above hadith is related by numerous authorities and were spread far and wide by many narrators. )
* The Prophet said: "Al-Mahdi is one of us, the members of the household (Ahlul-Bayt)." (ref: Sunan Ibn Majah, v2.4085)
* The Messenger of Allah said: "Al-Mahdi is one of the children of Fatimah." (ref: Sunan Ibn Majah, v2.4086)
* The Prophet said: "We the children of Abd Al-Mutalib are the Masters of the inhabitants of Heaven: Myself, Hamza, Ali, Jafar, Hasan, Hussain, and Al-Mahdi." (ref: Sunan Ibn Majah, v2.4087)
* The Prophet said: "The Mahdi will appear in my Ummah. He will appear for a minimum of 7 or a maximum of 9 years; in that time, my Ummah will experience a bountiful favor like never before. It shall have a great abundance of food, of which it need not save anything, and the wealth at that time is in great quantities, such that if a man asks the Mahdi to give him some, and the Mahdi will say: Here! Take!" (ref: Sunan Ibn Majah, v2.5083) Shi'ites believed that the world government the Mahdi is supposed to establish will last for hundreds of years, and then the day of judgement will come.
* The Prophet said: "We (I and my family) are members of a household that Allah has chosen for them the life of the Hereafter over the life of this world; and the members of my household (Ahlul-Bayt) shall suffer a great affliction and they shall be forcefully expelled from their homes after my death; then there will come people from the East carrying black flags, and they will ask for some good to be given to them, but they shall be refused service; as such, they will wage war and emerge victorious, and will be offered that which they desired in the first place, but they will refuse to accept it, until a man from my family (Ahlul-Bayt) appears to fill the Earth with justice as it has been filled with corruption. So whoever reachs that (time) aught to come to them even if crawling on the ice/snow." (ref: Sunan Ibn Majah, v2.4082, also in the History Tabari)
* The Messenger of Allah said: "The world will not perish until a man among the Arabs appears whose name matches my name." (ref: Sahih Tirmidhi, v9, p.74)
* The Prophet said: "What would be your situation if the Son of Mary transcended upon you and your Imam is among you?" (ref: Sahih al-Bukhari (Arabic), v4, p.143)
* The Prophet said: "There will come at the end of the time for my Ummah a Caliph where the abundance of wealth will be as great as there is sand, and is beyond count." (ref: Sahih Muslim, v2, part 2, under the topic of "the Day of Judgment will not commence until a man passes by the grave of a dead man, and wishes that he was in his place")
* The Messenger of Allah said: "Mahdi from my family will bring about a revolution and will fill the world with justice and equity before which it was filled up with injustuce and inequity." (ref: Musnad Ahmad Ibn Hanbal, v1, p.84 Jami'us Sagheer, by al-Suyuti, pp. 2,160 al-Urful Vardi, by al-Suyuti, p.2 Kanzul Ummal, v7 p.186 Aqd al-Durar Fi Akhbaar al-Mahdi al-Muntazir, v12, Chap. 1, al-Bayan fi Akhbar Sahib al-Zaman, By Ganji Shafi'i, Chap. 12 al-Fusool al-Muhimmah, by Ibn Sabbagh Maliki, Chap. 12 Arjahul Matalib, by Ubaidallah Hindi hanafi, p.380 Muqaddimah, by Ibn Khaldoon, p.266)
* The Prophet said: "Allah will bring out from concealment Mahdi from my Family and Progeny before the Day of Judgement, even if only one day were to remain in the life of the world, and he will spread on this earth justice, and equity and eradicate tyranny and opression." (ref: Musnad Ahmad Ibn Hanbal, v1, p.99)
* Mohammad Ibn Hanafiyyah and Imam Ali says that the Holy Prophet said: "Mahdi is from our Ahlul-Bayt, no doubt Allah will enforce his Amr (appearance) within a night (ie. his coming is very unpredicted)." (ref: Sunan Ibn Majah, v2, p.269)
* Author of Sahih Muslim reported on the authority of Jabir that Jesus will descend in the last days, and the Imam will ask him to lead in prayer, but Jesus will decline.
* al-Hafiz Ibn Hajar al-Asqalani mentioned that: "The Mahdi is of this Ummah, and that Jesus will come down and pray behind him." (ref: Fath al-Bari, by Ibn Hajar al-Asqalani, v5, p.362)
* "The Ahlul-Bayt are like the stars through whom we are guided in the right direction, and if the stars are taken away (or hidden) we would come face to face with the signs of the Almighty as promised (ie. the Day of Resurrection). This will happen when the Mahdi will come, as mentioned in the traditions, and the Prophet Jesus will say his prayers behind him, the Dajjal will be slain, and then the signs of the Almighty will appear one after another." (ref: Sawa'iq al-Muhriqah, by Ibn Hajar al-Haythami, ch11, p.91)
* Ibn Khaldoon (d. 808/1406), a Sunni historian, in his book "al- Muqadimah," wrote that: "Let it be known that it is a narrated event among the people of Islam throughout the ages that there must appear a man at the end of time from the family of the Prophet, who will strengthen Islam and spread justice; Muslims will follow him and he will gain domination over Muslim realm. He will be called al-Mahdi." (An Introduction to History, by Ibn Khaldoon, London, 1967, pp. 257-258)
* fatwa: Issued in Mecca by the Muslim World League (Rabitatul `Alamul Islami) on Oct. 11, 1976 (23 Shawwal 1396): "The memorizers (Hafiz) and scholars of Hadith have verified that there are authentic (sahih) and acceptable (hasan) reports among the traditions related to al-Mahdi. The majority of these traditions are related through numerous authorities (Mutawatir). There is no doubt that the status of those reports are Sahih and Mutawatir. (They have also verified) that the belief in Mahdi is obligatory, and that it is one of the beliefs of Ahl al-Sunnah wal Jama'a. Only those ignorant of the Sunnah and innovators in doctrine deny it. (see The Introduction of al-Ganji al-Shafi'i, in the book named "al-Bayan," Beirut, 1399/1979, pp. 76-79 and in Appendix.)