The course addresses a group of methods articulated by Usuli scholars for deriving Islamic legal rulings for different issues. These methods are related to the words/expressions divided by the usuli scholars from the four viewpoints; firstly, the origin meaning of the words, secondly, the use of words for a meaning, thirdly, their indication of a meaning, and fourthly, how do they indicate to a meaning. Hence, it focuses on the first viewpoint on specific expression, general expression, and homonym expression. Furthermore, it touches on the second viewpoint on the real meaning of an expression, the metaphorical meaning of an expression, direct expression, and indirect expression. Likewise, this course discusses in the third and fourth viewpoints texts of clear connotations and texts of unclear connotations, and also modes of implication from the uttered words of the text and modes of implication from the implicit meaning of the text.