The first sign of the Imamate

Abu Baseer narrates that he asked Imam Ar-Ridha’ (as) about the sign of an Imam. The Imam (as) replied, “The first sign of the Imamate is that the incumbent is the first born of the Imam. He is superior in knowledge, in learning, to all his contemporaries. The Armor of the Prophet (S) to be in his possession and would exactly fit him. He would also possess the Standard used by the Prophet (S). Amir’ul-Mu’mineen ‘Ali (as) had said, ‘The Prophet had taught to me a thousand chapters of learning, and from every chapter another thousand chapters became manifest to me.’”
Imam Ar-Ridha (as) further said, “O Abu Muhammad! I have the Jameah” I asked him, “What is Jameah?” The Imam (as) replied, “Jameah is a document dictated by the Prophet (S) to Amir’ul-Mu’mineen ‘Ali (as). This contains the details of everything that is legitimate (Halal) and taboo (Haram) for the believers.” Then the Imam said, “We have the Mushaf al-Fatima (the Book of Fatima). This Book is three times more voluminous than the Holy Qur’an and contains, besides the Qur’an, all the information about the past and about the times to come.”