Text linguistics emerged in the mid-20th century as a reaction to the limitations of traditional linguistics, taking the text as the unit of study instead of the sentence. Claus Brinker is among the most prominent pioneers in this field, presenting a communicative model that integrates linguistic structure and contextual aspects, enhancing comprehensive analysis. Given the importance of Arabic in the Iranian educational system, linked to the Quran and Islamic heritage, and the use of the book Arabic, the Language of the Quran 1 as core material for secondary literary and humanities branches, this book was chosen to study educational discourse and analyze language functions according to Brinker's model. The research aims to analyze the book’s content through content analysis, selecting a representative sample of units covering various topics. The study applied precise classification criteria for Brinker’s five language functions, manually coding and analyzing texts to determine each function’s proportion, enabling an objective evaluation of their distribution. Results revealed all linguistic functions were present but unevenly distributed, with the informative function dominating at 35/71%, while expressive and consultative functions appeared weak, reflecting a cognitive focus over emotional and communicative aspects. Although the book integrates knowledge, aesthetic, and social skills, the imbalance highlights the predominance of the informative aspect over communication and persuasion.