Undoubtedly, the use of modern linguistic theories for the analysis of religious texts can pave the way for a better understanding of such texts. Among the new theories which today have a special place and wide application in text analysis and other linguistic areas, is Systemic Functional Grammar (SFG) of Halliday and Matthiessen (2014). According to this theory, the structure of language is influenced by the functions that language plays in the communication context and in the outside world, and this effect is manifested in the form of three broad metafunctions: ideational, interpersonal and textual. Since the emphasis of interpersonal metafunction is on the way of exchanging meaning between the speaker and the audience, its application in the analysis of religious texts, while making a better understanding of such texts, can be an appropriate benchmark for assessing the ability to generalize this theory. Therefore, using a descriptive-analytical method in terms of the Systematic Functional approach of Halliday and Matthiessen (2014), the present study aims to analyze one of the most famous sermons of Nahj al-Balagha, i. e. Shaqshaqiya Sermon. The main results of the research show that, despite the dominant frequency of indicative mood, Imam Ali (AS) throughout this sermon has somehow acted in the exchange and transfer of meaning as if both sides of the interaction engage in the construction of the text, thus avoiding any kind of one-sidedness and unilateral. Moreover, since the sermon has been delivered by the motive and the purpose of establishing the right of the caliphate by Commander of the Faithfu.