The Just Leader of Humanity 6
(2) 'Ali b. 'Umar A'raj Kufi, a companion of Imam Kazim, wrote a book on ghaybat.
(3) Ibrahim b. Salih Anmati, a companion of Imam Kazim, wrote a book on ghaybat.
(4) Hasan b. 'Ali b. Abi Hamza, who lived during the time of Imam Rida, was also an author of a book on ghaybat.
(5) 'Abbas b. Hisham Nashiri Asadi was a prominent figure and a reputable person. He was among the companions of Imam Rida. He died in the year 220 AH/835 CE. He also wrote a book on ghaybat.
(6) 'Ali b. Hasan b. Faddal was a learned man and reliable in his transmission of religious information. He was among the companions of Imams Hadi and Hasan 'Askari. He wrote a book on ghaybat.
(7) Fadl b. Shadhan Nishaburi was among the jurists and theologians. He was among the companions of Imams Hadi and Hasan 'Askari. He died in the year 260 AH/873 CE. He wrote a book on the subject of the Qa'im of the Family of Muhammad and his ghaybat.
It is important to keep in mind that the story about ghaybat is not something new in Islam. It has deep religious roots and was always discussed and debated from the time of the Prophet (peace be upon him and his progeny). Consequently, the possibility that a person like 'Uthman b. Sa'id invented and disseminated it is absolutely unfounded. Such an accusation cannot come about from any one other than a prejudiced individual. Moreover, if we append the following three propositions together, then the matter of the occultation of the Imam of the Age becomes certain:
(a) On the basis of rational demonstration as well as numerous hadith-reports related from the Prophet and the Imams, it is certain that the existence of the Imam and the Proof of God on earth is necessary for the survival of humanity. Therefore, there is no time when the earth could be without the Imam.
(b) On the basis of numerous hadith-reports, there can be no more than twelve Imams.
(c) On the basis of many reports, both in the books on hadith and history, it is a fact that eleven of these twelve Imams have lived and died.