Who is Mehdi? Quran doesn’t mention Mehdi at all. In Hadith, Bukhari and Muslim refers him but his name doesn’t exist in any of them. Abu Dawud and Tarmidhi mention his name in their collections referring the Prophet (PBUH), so Mehdi has become part of the Islamic faith.
In the Arabic language Mehdi is a name however in his case it will be not name, but title which means: righty guided. According to Hadith his real name will be Mohammed and his father’s name Abdullah, exactly as it was in case of our Prophet (PBUH): Mohammed ben Abdullah.
Mehdi will come at time of final judgement when injustice and wrong-doing prevails on earth. The presence of Mehdi will be the last one among the minor signs before Last Judgement. If he comes everybody will know that major signs should be expected of which the first will be the arrival of Dajjal, the Antichrist. Muslims under leadership of Mehdi will not be able to defeat Dajjal, no matter of the fights what they wage against him. Dajjal will be defeated only by Jesus, son of Mary whose advent represents the second major sign of Last Judgement shortly after the arrival of Dajjal.
However, let’s see who is Mehdi and what characteristics he has? It is important because he is a pattern for us. Mehdi is and ordinary man who conducts a fallible life as anybody else. He has no idea at all of being Mehdi. I have to emphasize that he is fallible, therefore he is not a sacred man! He lives in Medina and one night the Lord calls him. Since this call his life changes, but very important: he never declares about himself to be Mehdi! In fact, he denies it! People declare him as Mehdi. He argues with them and wants to avoid being marked as Mehdi. And here you are the instruction for all of us! Never believe for anyone who sets up a particular position for himself as if it was created for him. Whoever declares himself Mehdi is a liar!
Ahl al-Sunna and Ahl al-Shite follow different traditions regarding the ascendency of Mehdi. They both agree that he comes from the household of the Prophet (PBUH) and his forefather is one of the sons of Ali and Fatima (daughter of Prophet, peace be on them). Sunnis say that this forefather was Hasan while Shite say he was Hussein.
Time comes when Mehdi has to flee from Medina to Mecca. So, not from Mecca to Medina as Prophet (PBUH) did, but just in contrary. Later, troops of Muslims from Medina will depart to destroy the Kaaba. They go towards Ajiyad but at Beida the earth will open and swallow them up. This event is mentioned in Hadith Bukhari. Even in this Hadith name of Mehdi doesn’t exist. However, if we put it together with reference of Abu Dawud where name of Mehdi is referred to, the whole event comes together. According to Abu Dawud, Mehdi seeks refuge at Kaaba and people here take an oath of allegiance to him. They recognize him as Rightly Guided Imam. But, political leaders of his age refuse him stigmatizing him as rebel and send troops against him. The devastation of this troop will be the evidence that the person who will be with us is truly Mehdi.
Here you are another lesson: “With exception of its own people, nobody else wants to destroy Kaaba”, says the Hadith. Never can happen that a non-Muslim army would attack the Kaaba. We must be sure about that. Until Muslims exist in earth, nobody will be able to destroy Kaaba. In fact, even a single attempt will be not committed. Only Muslims will try to do that. This is what Mohammed (PBUH) predicted.
But time will come when Kaaba will be destroyed. When? It will be destroyed by an army which comes from the direction of Ethiopia when there will be not even one Muslim on the earth. This will be the end of times when trumpets will be sound on the day of doom.
Back to Mehdi. Mehdi will be the Imam of the whole Umma.
According to a Hadith an army of Romans (western people) will departs and finally they set their camp up in Syria at a place called Dabiq. Another troop departs from Medina and they wage war with Romans at Dabiq. This will be the great Armageddon. Then, troop of Mehdi turns towards Constantinople (Istanbul) and occupy it. Nobody can explain this Hadith so far; however, it is authentic from collection of Muslim. The same Hadith in collection of Tarmidhi declares the site’s name is Jerusalem, but Tarmidhi is not authentic.
Mehdi unites the Muslim world and establishes peace and justice everywhere. He tries to gain victory over Dajjal but he fails.
This is the time when Jesus descends from Heaven at time of Fajr (dawn) prayer. Where? In Damascus at the white minaret according to the Hadith. When this Hadith was revealed this minaret had not been yet built. It is the Omayyad Mosque what was raised by Abdel Malik Marwan and the Hadith refers to this place. This mosque is 1350 years old at the moment. Mehdi will recognize Jesus and asks him to lead the prayer, but Jesus refuses it saying: the iqama (call for prayer) is for you, so you have to lead prayer. “Your imam is from you”. (Hadith Muslim)
Then comes role of Jesus: he is the only one who will be able to kill Dajjal and finally he will do it. Mehdi will reign for seven years. He will live even further but his administration will last for seven years. After Jesus descends from Heaven and fulfills his duty there is no more Hadith about Mehdi.
The above words are teachings from our Prophet (PBUH) who foresaw the events of Last Judgement and its signs 1400 years ago.