Has the Shi‘a school been discussed in the speech of the religious leaders before Imam as-Sadiq (peace be upon him)?
As we mentioned before, Shiaism is an genuine Islamic school introduced by the person of the Holy Prophet (peace be upon him and his family), and all can understand this point from the matter found in Nahj al-Balaghah and the sayings of Amir al-Mu’minin (peace be upon him).
Imam Muhammad al-Baqir (peace be upon him) and Imam Ja‘far as-Sadiq (peace be upon him) explained the various dimensions of this school for the people and perfected the people’s information about it and eliminated the over- and under-exaggeration existing regarding this issue.
They demonstrated that the principle of Imamah was an genuine and entirely Islamic concept and the reference point of explaining its reality and limits are the Imams (peace be upon them), just as they are the reference for explaining all Islamic concepts and terminology and Qur’anic verses. When their unparalleled and great-learned position became apparent, all understood that those eminent men possessed all abilities and at the same time were the sole reliable source in recognizing the principle of Imamah and its entire and original concept. Of course, this does not mean that we should presume that the principle of Imamah was their innovation or, as some who do not believe in the unseen world say, a product of history.
Among the reliable traditions according to Ahl al-Sunnat are the traditions of ‘Ali ibn Husayn (peace be upon him), Imam Muhammad al-Baqir (peace be upon him), and Imam Ja‘far as-Sadiq (peace be upon him); as Ahmad Shakir has written in his commentary of al-Ba`ith al-Hathith, the spiritual position and Imamah of the Imams before these two Imams was very firm in the hearts of the people.
The belief that the Imams are al-Qur’an al-Natiq (the Qur’an that speaks), i.e. they know the specific Qur’anic meanings and expressions, was raised on numerous occasions previous to Imam Muhammad al-Baqir (peace be upon him) in the words of his noble father Imam ‘Ali Zain al-‘Abidin (peace be upon him) and before him in the traditions of Amir al-Mu’minin (peace be upon him), Imam al-Hasan (peace be upon him), and Imam al-Husayn (peace be upon him). The Prophet (peace be upon him and his family) has pointed to this issue in traditions that have passed the limit of tawatur (consecutive narration) and he (peace be upon him and his family) introduced the Imams as equals of the Qur’an. In the books of Ahl al-Sunnat, a sermon has been narrated from Imam ‘Ali Zain al-‘Abidin (peace be upon him) in which the placing of Imamah in Ahl al-Bait (peace be upon them) and their being the sole referral authority and Divine authority for mankind has been discussed explicitly and in depth.