It has been commonly accepted amongst some scholars that Islamic law lacks of procedure and that it had indebted greatly to the system known in the secular system of law. This essay attempts to analyze the origin of the idea of the law procedure by tracing the very early concept found in the genre of Kitâb al-Qâdhî ilâ al-Qâdhî (a letter form one judge to another judge) incorporated in the legal literature of fuqahâ' or Islamic jurisprudents. The study is a qualitative research by in depth analysis on legal materials on the letter of a judge to another judge found in the works of various Islamic law scholars. The finding of this study implies that despite the over-simplication of some scholars on the Islamic law of evidence, there exist a very complex discussion of the issue in the works of Islamic law scholars. It is conceivable to assert that this historical record of law of evidence in Islam had become an integral part of the social and legal practices of the early time that could be regarded as the early inception of law of evidence in Islam.