Extracting the Usuli foundations of some Islamic jurists, including Mohaghegh Khansari, who have not left an independent Usuli work, is of special importance. In this research, in addition to examining one of the most widely applied issues of Usul al-Fiqh, namely ascertaining how an absolute term denotes absoluteness, his foundation in this regard has been analyzed and studied. The authors, after scrutinizing the Usuli books and Jami al-Mdarik fi Sharh Mukhtasar al-Nafi book, have come to the conclusion that the denotation of absoluteness by the absolute term is not due to convention; rather, it is realized with the help of the rational proof and through Muqaddimat al-Hikma (premises of wisdom). Such premises consist of the possibility of absoluteness and qualification, lack of evidence on qualification, the speaker being in the position of depiction and the absolute word not being indicative to certain instances; additionally, when relying on absoluteness, it is not necessary that the established amount is absent while addressing; instead, basically, the existence of the established amount while being in the position of addressing is non-sense.