The rank of qadi (judge), and that of the administrator of justice have great importance, and in fact these are ranks worthy of great respect. In the Imamiyah sect, the responsibility of the judiciary is considered an adjunct of the prophethood, the imamate and the state in general.
God, the Almighty has said, "O David. We have appointed you vicegrent in the earth; so judge between the people with justice." (38:26) And again He says, "By the Lord (O Prophet), they believe not until they have set you up and their judge in all that they dispute about among themselves, and thereafter find not in their selves any vexation against what you decide, and submit with total submission." (4:65)
The qadi and judge are the nawamisu' th-thalathah (custodians of three things - life, property and honour). That is why there are serious dangers in this rank at every step, and if the texts of the traditions are carefully studied, we shall find that it is so exalted a rank that even the mountains seem to be insignificant before it.
Hadhrat Amir al-Mu'minin (a.s.) says, "The qadi should be considered to be on the brink of Hell. The qadi's tongue is between two balls of fire. O Shurayh, you are sitting at a place where sits either a prophet or his "wasiy" (successor) or else some wicked person." It is stated in a tradition of the Propeht (s.a.w.), "If somebody is made a qadi it means that he has been slaughtered without a knife." There are many traditions of this nature.
If a ruling which a "faqih" (expert in jurisprudence) deduces from proofs concerns some general principles, it is called a "fatwa"; for instance, it is unlawful to use someone else's property without his or her permission, the wife of a man is lawful to him but she is unlawful to a stranger. But if the order pertains to some particualr case it is called a judgement (qada); for instance, "This woman is the wife." "This woman is a stranger." "This is Zayd's property." "That is the property of such and such a person."
Whether it is a "fatwa" or a "qada", both of them are duties of a just mujtahid who is the general proxy of the Imam.
Judgement is in fact the identification of the legal nature of points under dispute, whether they pertain to defense and accusation in a court, or to matters such as the sighting of the moon and the determination of the beginning of the month, or the administration of endowments and the determination of lineage, and it demands great wisdom and intellectual ability. In fact it is more difficult a task than issuing a "fatwa".
Now, if somebody who is devoid of these qualities undertakes to perform this duty, it will certainly do more harm than good. Accordingly, it is unlawful in Imamiyah "fiqh" for anyone except a just mujtahid to undertake to perform this work. Indeed, it is regarded as one of the major sins if anyone else does do it, and the extent of its enormity borders on infidelity. Our respected teachers used to be very cautious about passing judgements. We also follow the same line.
Judgement can only be passed on the basis of three things: (1) confession (iqrar), (2) an oath (qasm), or (3) two just witnesses (bayyinah). The question of how to establish preference or priority in cases where there may be difference or contradiction between the witnesses is a matter for the section of fiqh which deals with the giving of evidence, and there is little point in going into the details here. Suffice it to say that the matter has been examined in great detail by our jurists and they have left many writings on it. We, also, have written a book on the subject called "Tahriru 'l-majallah".
One who does not act in accordance with the order or of the authorized "qadi" (i.e. one who fulfills all the conditions of a "qadi") will be considered to have violated the divine commands. Also no one has the right to revise the decision of a "qadi". Of course, the qadi himself may re-examine his judgement.
