In fact to use the term " hadith " in Sunnism is to refer to...

In fact to use the term " hadith " in Sunnism is to refer to his sayings and not to anyone else's. In the case of Shi'ism, however, although a clear distinction is made between prophetic Hadith ( al-hadith al-nabawi ) and the sayings of the Imams ( al-hadith al-walawi ), the two are included in a single collection.

This means that from a certain point of view the apostolic age of Islam is seen by Shi'ism to stretch way beyond the relatively short period usually associated with apostles in various religions. The reason for this perspective lies of course in the Shi'ite conception of the Imam.[^2] The term imam as used in a technical sense in Shi'ism differs from the general usage of the term in Arabic, where it means "leader", or in Sunni political theory where it means the caliph himself.

As used technically in Shi'ism the term refers to the person who contains within himself the "Muhammadan Light" ( al-nur al-muhammadi ) which was handed down through Fatimah, the daughter of the Blessed Prophet, and 'Ali, the first Imam, to the others, terminating with the Hidden Imam who is to appear again one day as the Mahdi.[^3] As a result of the presence of this light, the Imam is considered to be "sinless" ( ma'sum ) and to possess perfect knowledge of the esoteric as well as the exoteric order.

The Imams are like a chain of light issuing forth from the "Sun of Prophecy" which is their origin, and yet they are never separated from that Sun. Whatever is said by them emanates from the same inviolable treasury of inspired wisdom. Since they are an extension of the inner reality of the Blessed Prophet, their words really go back to him.

That is why their sayings are seen in the Shi'ite perspective as an extension of the prophetic Hadith , just as the light of their being is seen as a continuation of the prophetic light. In Shi'ite eyes, the temporal separation of the Imams from the Blessed Prophet does not at all affect their essential and inner bond with him or the continuity of the "prophetic light" which is the source of his as well as their inspired knowledge.

This metaphysical conception is the reason that Shi'ites incorporate traditions stretching over two centuries into a single whole with those of the Blessed Prophet himself. It also distinguishes the Shi'ite conception of Hadith from that held in Sunnism. Otherwise, the actual content of Hadith in Sunni and Shi'ite collections is very close. After all, both kinds concern the same spiritual reality.