The Prophet further elaborates, “Beware of doubting, for to doubt the order of God, the Mighty, the Sublime, is apostasy (Kufr). Ibn Khaldun also states that “When imprisoned with his mother in the house, he entered a sort of well or pit in the house that his family occupies at Samarrah, Iraq, and there he disappeared, but he is to come forth at the end of the age to fill the earth with justice”.
Allama Jalaluddin Suyuti quotes in his book Jalalul- Oyun Vol.6 page 50. “The Hour shall not come till Al-Mahdi takes charge on earth on my behalf,” said the Messenger of God. Allama Suytu also quotes Imam Ahmed ibn Hanbal that famous companion Abu Said Khadhri quoting the Messenger of God saying, “I bring you glad tidings of al-Mahdi, God shall send him to my nation, in a time different from your own, and after a series of earthquakes, and he shall fill the earth with justice and equity as it was filled with injustice and oppression. He shall distribute the wealth equitably among the inhabitants of the earth. In the manual in which he sets forth the many duties and privileges of pilgrims, Majlisi has given an accepted form for a short letter in Arabic, which anyone can write, and sent to his Imam of the age. It may be placed on the tomb of any of the Imams, or it may be fastened and sealed, and covered with clean earth and cast into the sea or river or a deep well. In any case it will reach the Hidden Imam and he will give his personal attention. There is a famous saying of Imam Hussein (A.S) about the twelfth Imam. “The Ninth of my descendants is the Imam who will rise with the Truth. God will grant life to earth through him after its death. The true faith will supersede all religions through him. His absence shall be lengthy during which many people will go astray. Only a few will remain on the Right Path. They shall suffer pains; people will put pressure on them, saying, "let us know when this promise of the Return of the Mahdi is fulfilled". Those who will bear the pains and denials patiently will get the same rewards as those who accompanied the Prophet during his expeditions for Jihad.”
Imam Imam Sadjad (A.S) has said, “Of us one will be born whose birth will remain secret so much so that the people will say that he was not born at all.”
Imam Muhammad Baqir (A.S) is quoted by Kulaini in Al-Kafi, “Nine Imams after Hussein are destined, and the last of them will be al-Qaim.” Imam Ja’far Sadiq (A.S) is quoted in Ilal al-shaa’i saying, “The fifth of the descendants of my son Musa will be the Qa’im a descendant of the Prophet (A.S). Imam Kadhim (A.S) was asked once, “Are the Qa’im with the truth?” The Imam replied, “I also rise truthfully, but the real Qa’im is he who will remove the enemies of God from earth and will fill it with justice. He shall be my fifth descendant. His absence will be lengthy during which multitudes will turn away from the faith while only a few will uphold it”. Imam Reza (A.S) in the above saying of Imam Hussein (A.S) that due to the excessive the length of the concealment of the 12th Imam many believers will have doubts about his existence. Many will question the very longevity of his life and the usefulness of his presence as an Imam Rida (A.S) said, “O Da’bil, my son Muhammad (A.S) will come when I am gone. After him, his great grand son will be named Muhammad (A.S) who will be the Qa’im. He will be awaited during his absence. When he appears, the world shall bow down before him.” Imam Muhammad Taqi (A.S) has said “The Qa’im will be from amongst us the third of my descendants”. Imam Ali Naqi (A.S) said, “My successor will be my son Hassan; but what will be your condition during the reign of Hassan’s successor”? Those who were present asked, “Why, what do you mean by that”? Imam replied, “You will not have the chance to see him, later you will not be allowed to mention his name”. Then the Imam was asked as to how they should mention him. Imam replied, “You may say that he is the last of Muhammad’s (PBUH) (infallible) descendants. “Some people asked Imam Hassan Askari (A.S), “Your forefathers have said that the earth would never be without knowing the sign of Allah (Hujjatullah) till Doomsday, and he who dies without knowing the Imam of his time will die the death of ignorance”. Imam replied, “That was as true as the shining day. They inquired as to who would be the Imam who would be the sign of the Mercy of God after his death, Imam replied:
“He will be my son, the namesake of the Holy Prophet (Muhammad Abul Qasim). He who died without knowing him will die the death of ignorance. His absence will be so lengthy that the ignorant will wander puzzled and would surely stray from the Right Path. But the Righteous shall remain steadfast and pray for their Imam to appear within their life time”.
All these predictions were recorded since the time of the Holy Prophet who himself prophesied the advent of the Mahdi. (Read this Hadith in the story of the 5th Imam). As in the above saying of Imam Hussein (A.S) that due to the excessive length of the concealment of the 12th Imam many believers will have doubts about his existence. Many will question the very longevity of his life and the usefulness of his presence as an Imam.
* Source: coiradio.com