After him will follow Hassan and after Hassan shall come...
After him will follow Hassan and after Hassan shall come Hujjat Qaem the one for whom the people will await during his occultation and the one who will be obeyed during his reappearance. He will fill the earth with equity and Justice just as it had been filled with cruelty and oppression.
About his uprising, my father has narrated from my grandfathers who in turn have narrated from the Holy Prophet (S.A.W.A.) that: "The example of (emergence of) Mahdi is like the example of Qiyamat which shall occur all of a sudden." The author of the afore-said book (on page 488) has narrated from the book "Ghayat-ul-Maram" which in turn has narrated from the book "Fare'ed-us-- Semtain" that Jaber-ibn-Abdullah Ansari has quoted the Holy Prophet (S.A.W.A.) as saying: "Mahdi shall come from my progeny.
His name and agnomen shall be the same as my name and agnomen. Amongst all the people, he shall resemble me the most in appearance and character. There shall occur an occultation for him due to which nations shall deviate. Mahdi will emerge like a twinkling star and fill the earth with equity and justice to the reverse extent it had been filled with cruelty and oppression. Again on the same page of 'Yanabi-ul-Muwadda' he (i.e.
Shaikh Qunduzi) narrates from 'Fara'ed-us-Semtain' from Imam Muhammad Baqir from his grand-fathers from Ali-ibn-Abi Talib that the Holy Prophet (S.A.W.A.) said: Mahdi is from my progeny. There shall occur an occultation for him due to which nations shall deviate... He shall fill the earth with equity and Justice just as it had been filled with cruelty and oppression.
On page 493 of the same book he has narrated from the book 'Manaqib' which in turn has narrated from Imam Muhammad Baqir that the Holy Prophet (S.A.W.A.) has said: "Blessed is the one who perceives the 'Qaem' from my Ahl-e-Bayt and believes him to be the Imam during his concealment (i.e. before his emergence) and befriends his friends and alienates his enemies. Such a person shall be amongst my lovers and companions and they are the best of my people on the Day of Judgement.
The author of the same book narrates from Abu Baseer who narrates from Imam Jafar Sadeq who narrates from his great grandfather who in turn narrates from Amir-ul-Mumineen that the Holy Prophet (S.A.W.A.) has said: Mahdi is from my progeny. His name shall be the same as mine and his agnomen too shall be the same as my agnomen. Amongst all the people he shall resemble me the most in appearance and character.