In the Sasanian period private and criminal procedural law were distinguished in practice, though not in theory. Sasanian law elaborated rules to prevent the guardian misusing his position and gaining material or legal benefit from his position when a clash of interests between the family and its guardian representative emerged. It is remarkable that in private litigation reference to ordeals is rather unusual, while in cases of capital crimes it was more frequent. Besides litigation Islamic, Jewish and Zoroastrian courts had a variety of administrative and social functions. To reconstruct Zoroastrian criminal procedural law one must rely on a variety of sources, such as the Syriac Acts of Martyrs, religious and secular literary works, and sometimes even pamphlets of dubious historical reliability. Rabbinic sources see the Sanhedrn as an organ of the administration of justice having legislative functions, too. Waqfs can be regarded as one of the most important private law institutions of Islamic law.