Sunni Documentation on Imam al-Mahdi A.S
For the Sunni brothers, there are six major collections of traditions based on the Sunni standards for verifying the authenticity of a tradition. These six books are: Sahih al-Bukhari, Sahih Muslim, Sahih al-Tirmidhi, Sunan Ibn Majah, Sunan Abu Dawud, and Sahih al-Nisa'i. I just quote few traditions from these six books to prove that a knowledgeable Sunni brother/sister can NOT deny that:
al-Mahdi (A.S) will come in the last days to make a universal Government,
al-Mahdi (A.S) is from the Ahlul-Bayt of the Prophet (PBUH),
al-Mahdi (A.S) is from the progeny of Fatimah (A.S), the daughter of the Prophet (PBUH),
al-Mahdi (A.S) is different than Prophet Jesus (the Messiah),
Prophet Jesus (A.S) will come as one of the followers of Imam al-Mahdi and will pray behind him in congressional prayer.
Another undeniable fact is that many leading Sunni scholars have written books after books exclusively about Imam al-Mahdi (A.S) which I included some of their names at the end of this article.
Moreover, Insha Allah in the next article, I will give a list of Sunni scholars who believe that Imam al-Mahdi (A.S) is son of Imam Hasan al-Askari (A.S), and is alive and went into occultation. In that article will also discuss the special specifications of Imam al-Mahdi which are the points of disagreement between the Shia and the Sunni.
The following are only some of the traditions about Imam al-Mahdi which Sunnis admit to their authenticity and existence:
The Prophet (PBUH) said: "Even if the entire duration of the world's existence has already been exhausted and only one day is left (before the day of judgment), Allah will expand that day to such a length of time, as to accommodate the kingdom of a person from my Ahlul-Bayt who will be called by my name. He will fill out the earth with peace and justice as it will have been full of injustice and tyranny (by then)."
Sahih al-Tirmidhi, v2, p86, v9, pp 74-75
Sunan Abu Dawud, v2, p7
Musnad Ahmad Ibn Hanbal, v1, pp 84,376; V3, p63
al-Mustadrak ala al-Sahihayn, by al-Hakim, v4, p557
Jami' al-Saghir, by al-Suyuti, pp 2,160
al-Urful Wardi, by al-Suyuti, p2
al-Majma', by al-Tabarani, p217
Tahdhib al-Tahdhib, by Ibn Hajar al-Asqalani, v9, p144
Fat'h al-Bari fi Sharh Sahih al-Bukhari, by Ibn Hajar Asqalani, v7, p305
al-Sawa'iq al-Muhriqah, by Ibn Hajar al-Haythami, Ch. 11, section 1, p249
al-Tathkirah, by al-Qurtubi, p617
al-Hawi, by al-Suyuti, v2, pp 165-166
Sharh al-Mawahib al-Ladunniyyah, by al-Zurqani, v5, p348
Fat'h al-Mugheeth, by al-Sakhawi, v3, p41
Kanz al-Ummal, v7 P186
Iqd al-Durar Fi Akhbar al-Mahdi al-Muntadhar, v12, Ch. 1,
al-Bayan fi Akhbar Sahib al-Zaman, By Ganji al-Shafi'i, Ch. 12
al-Fusool al-Muhimmah, by Ibn Sabbagh al-Maliki, Ch. 12
Arjahul Matalib, by Ubaidallah Hindi al-Hanafi, p380
Muqaddimah, by Ibn Khaldoon, p266
and also in the works of Ibn Habban, Abu Nua'ym, Ibn A
Mahdi (AS) in Different Ahatith