the Muhammadan Light from one Imam to the other. The Shia idea that the succession should continue in the descendants of the prophet originates from the Quran as verse 4:54. Ismah Shia believe that Ismah is a logical prerequisite of Imamah as Allah has made their obedience necessary and the verse 33:33 proves Ismah of the fourteen infallible. Ismah in addition to sinlessness means infallibility, without error. Imam by virtue of Nass based on Hikmah (wisdom) and Nur (light) becomes Ma'sum (Infallible). Hikmah (wisdom) The Imam has a perfect knowledge about religion and mankind. The Imams are the most knowledgeable in religious law and the rewards and punishments of the next world. They understand the literal meaning and the internal meaning (Ta'wil) of the Quran. Some Hadiths state the link between Allah and the Imams is a pillar descending from the heaven. The sources of the knowledge of Imam are the transmission from the previous Imam, inherited knowledge, acquired through angels and acquired from books whose contents are known only to the Imams. According to some Hadiths, Imams possess several special books including Al-Jafr (The Divination), Al-Sahifa (The Book), Al-Jamia (The Compilation), Book of Fatimah and a codex of Quran and its commentary (Mus'haf of Ali) written by Ali. He has the knowledge of the Greatest Name of Allah. As Imams are the manifestation of the attributes of act (fi'l) of Allah, their Knowledge is equivalent to the Knowledge of Allah. Imams have all the revealed books of the prophets. As Sayyid Haydar Amuli states: "All the Imams are one and the same Light (nur), one and the same Essence (haqiqah), exemplified in twelve persons." The hereditary character of nass embodied in itself a kind of exclusive Hikmah for its recipient which was traced back to Ali of whom the prophet told "I am the city of knowledge and Ali is its gate". Ibn Babaway states that "the title Amir al-Momenin reserved for Imam indicates that he is the storehouse (mirror) of knowledge (mira't al-ilm) from whom people derived knowledge but he did not derive knowledge from anyone else." Only Imam has knowledge of Unseen (Ilm al-Qayb) and fully understands Quran and worldly matters, a knowledge that he received from Allah through Muhammad. Only Quran and Imam can truly manifest the Divine Truth. Afdaliyyah (superiority) As the Imam is infallible (masum), he is the best of his age, otherwise, Allah