Discourse analysis is the result of the interactions of the linguistic and non-linguistic, intellectual and cultural competences as well as the interaction or the opposition of the ideologies. It analyzes the inner layers in the text to achieve its deep meanings. Using a descriptive-analytic method, the present paper implements the discourse analysis based on the prominent orientation and the marginalization of the Van Dyke's ideological square to analyze the debates of Imam Reza (AS) and Catholicos while proving the issue of prophecy. In selecting the words, Imam (AS) has used vocabularies with deep semantic load and has implemented the linguistic implications to transfer the meaning. Therefore, the selection and order of the words and the various types of emphases and the opening and the destination of words played a significant role in highlighting the main concepts that Imam called for. Imam used some techniques that caused doubts or questioned the beliefs of the other party and in this way he marginalized the discourse.