As a faith and a way of life, Islam includes among its most important objectives the realization of justice and the eradication of injustice. Justice is an Islamic ideal under all circumstances and at all times. It is not to be affected by one's preferences or dislikes or by the existence (or absence) of ties of blood. Rather, it is a goal to be achieved and an ideal to be sought: "Surely, Allah commands justice and the doing of good" (Qur'an 16:90); "And I was commanded to deal justly between you" (42:15); and "Allow not your rancor for a people to cause you to deal unjustly. Be just, for that is closer to heeding" (5:8). There are also many hadiths in the Sunnah that command justice and prohibit wrong. Moreover, the achievement of justice is one of the objectives towards which human nature inclines, while its opposite - injustice - is something that humans naturally abhor.
Allah has ordained measures by which justice may be known and by which it may be distinguished from its opposite. He has clarified the means by which all people might achieve this objective, facilitated the ways by which it may be accomplished, and made those ways (the most important of which is the institution of judgment, manifest to them. Allah prescribed the institution of legal judgment "that men may stand forth in justice" (57:25). This institution ensures that everything will be measured by the same criteria, which would make it impossible for one to be unjust to another's person or wealth. As a result, all people will live in the shade of peace and justice, where their rights am protected and where contentment envelops their hearts, souls, persons, honor, and wealth.
Historical Development of the Judiciary
The judiciary has been a firm religious responsibility and a form of worship from the time the Prophet initiated it by establishing the first Islamic state in Madinah. This is clear from the treaty between the Muslims, both the Muhajirun and Ansar, and their Jewish and polytheistic neighbors. In the treaty, it is written that "Whatever occurrence or outbreak is feared will result in corruption shall be referred for judgment to Allah and to Muhammad, His Prophet."
During the Prophet's reign Madinah was small, and the community’s legal problems were few and uncomplicated. And so there was a need for only one judge (qadi) - the Prophet. But when the territories ruled by Muslims began to expand, the Prophet began to entrust some of his governors with judiciary responsibilities and permitted some of his Companions to judge cases. He sent them to different lands and advised them to seek justice for the people and to oppose inequity. 'Ali was sent as a judge to Yemen, and others, such as Abu Musa and Mu'adh, became judges. The judgments passed by the Prophet were always based on what Allah had revealed to him.
In most cases, the two disputing parties would agree to present their case to the Prophet. After listening to both sides, he would tell them that he was deciding their case solely on the basis of the externals (i.e., evidence and testimony). He was careful to explain that his decisions should not be cited in order to permit what was prohibited or to prohibit what was permitted. He explained the proof and evidence and the means of defence and denial: "Proof is the responsibility of the claimant; whereas, for the claimed against, an oath is sufficient."' confession, with all of its conditions, is proof against the confessor. No judgment is to be passed between two disputing parties until both have been heard. The Prophet had no apparatus to collect and verify evidence to the advantage or detriment of either party.