Knowing the juristic rules is the main concern of Fiqh books and aim of usul al–fiqh where the scholars have paid more attention in particular for the juristic rules concerned with the intentions of the Legislator and interests of peoples. This manuscript is a response for this need, few papers written in usual al–fiqh where the writer added to the notes of his master related to true rule and positive rule. It also deals with rule as related to defy the rule and the effect of fiqh doctrines differences on such issue. There have been many writings in this field and this study aims at revising this manuscript properly according to modern study rules.