Anyone who traces the fiqh of Imamite Shi`as will find the latter referring in all juristic injunctions__with the exception of those relevant to our modern time1__to the Prophet through the avenue of the Twelve Imams from his Ahlul Bayt, peace be upon them. They have two, and only two, such sources, namely: the Book of Allah and the Sunnah.
By the first I mean the Holy Qur'an, and by the Sunnah I mean the Sunnah of the Prophet, blessings of Allah and peace be upon him for having brought it to his nation and the world. This is what the Shi`as have always been saying, and they are the statements of all the Imams from Ahlul Bayt who never claimed, not even once, that they acted according to their own personal views.
Take, for example, the first Imam Ali ibn Abu Talib: When they selected him to be the caliph, they preconditioned his government to be based on the “Sunnah” of both Shaykhs, namely Abu Bakr and Umar, yet he insisted on saying, “I do not rule except in accordance with the Book of Allah and the Sunnah of His Messenger.2
In our forthcoming researches, we will explain how he, peace be upon him, always followed the Sunnah of the Prophet to the letter, not going beyond it at all, trying by all means and might to bring people back to it, so much so that this caused the anger of some caliphs and the aversion of the populace from him due to his strictness in following Allah's Commandments and his upholding the Sunnah of the Prophet.
Imam al-Baqir, too, used to always say, “Had we followed our own views in your regard, we would have become misled just as those before us have, but we tell you about our Lord's clear argument which He had explained to His Prophet who, in turn, explained it to us.” On another occasion, he said to one of his companions, “O Jabir! Had we been following our own view and desire in dealing with you, we would have perished; rather, we tell you according to ahadith from the Messenger of Allah which we treasure just as these folks treasure their gold and silver.”
Imam Ja`far al-Sadiq has said, “By Allah! We do not say what we say according to our own desires, nor do we pass our own judgment. We do not say anything except what our Lord has said; so, whenever I provide you with any answer, it is from the Messenger of Allah; we never express any of our own views.”
People of knowledge and scholarship know such facts about the Imams from Ahlul Bayt; they never recorded one single statement made by any of them claiming to follow his own view, or resorting to analogy, or to preference..., or to anything besides the Holy Qur'an and the Sunnah.
Even if we refer to the great religious authority the martyred Ayatullah Muhammad Baqir al-Sadr, may Allah be pleased with him, we will find him indicating in his book of instructions (risala) to his followers titled Al-Fatawa al-Wadiha (the clear religious verdicts) the following:
We find it essentially important to briefly point out to the major references upon which we relied in order to derive these clear verdicts which, as we indicated when we started this discussion, are: the Glorious Book of Allah and the sacred Sunnah as transmitted by reliable transmitters who fear Allah when transmitting anything regardless of their sect.3
As for analogy, or preference, or the like, we see no legislative basis for depending on them. As for what is called the rational evidence about which mujtahids and scholars of hadith differed, whether or not it should be acted upon, although we believe that it can be acted upon, we never found even one legislative injunction whose proof depends on the rational evidence applied in such sense.
Instead, anything rationally proven is also fixed at the same time by the Book of Allah or by the Sunnah. As for what is called consensus, it is not a [third] source besides the Book of Allah and the Sunnah; rather, it is not relied upon only because it can sometimes be used as a means to prove certain points. Hence, the only two sources are: the Book of Allah and the Sunnah, and we supplicate to Allah to enable us to uphold them, for “Whoever upholds them upholds the secure niche which is never loosened, and Allah is all-Hearing, all-Knowing.”4
Yes, we find this to be the dominant phenomenon prevailing upon the Shi`as in the past and the present, and they do not depend on any source other than the Book of Allah and the Sunnah, and we do not find even one of them issuing a verdict based on analogy or preference. The incident involving Imam al-Sadiq and Abu Hanifah is well known.
It demonstrates how the Imam prohibited Abu Hanifah from applying analogy in deriving verdicts. Said he, “Do not use analogy with regard to the religion of Allah, for if you apply analogy to the Shari`a, it will be obliterated. The first person who applied analogy was Iblis when he said, `I am better than him: You created me of fire while creating him of mud.'“
These are the legislative sources of the Shi`as since the time of Ali ibn Abu Talib and till our time; so, what are the legislative sources of “Ahlul Sunnah wal Jama`ah”?