The attention to the deductive method began with Imam Al-Ash’ari and the establishment of the rules of theorizing from the first moment of the emergence of the Ash’ari school of thought at the hands of the founder of the school of thought, Abu Al-Hasan Al-Ash’ari, and the scholars who followed after him who wrote theological works. This reflects the great care of the Ash’arism in rooting and theorizing the methods of theory, and setting the methodological rules of reasoning, so he dealt with The research examines the most important comprehensive theological rules through which the Ash’ari reasoned in the doctrinal issues on which Ash’ari theological thought was founded, taking into account the extent of stability or change that occurred in some of these rules along the path of the Ash’ari doctrine. The aim of this study was to answer an important methodological question in formulating the verbal thinking curriculum: It is: What is the impact of comprehensive verbal rules in achieving intellectual consistency and methodological consistency in the theory of verbal reasoning according to the Ash’arism between theory and application? The answer to the nature of this research required delving into the journey of exploring the idea of comprehensive verbal grammar in the theological heritage. It was appropriate for this task to adopt the historical approach in collecting the material and searching for comprehensive grammar in its context from the verbal works approved in the Ash’arite school. It was necessary to study the origins of the theory of verbal grammar. Comprehensive and anticipating the methodological features governing inference, adopting the analytical approach; The approach adopted in this study was a combined approach of the two approaches: historical and analytical, in order to reach the impact of comprehensive verbal rules in both theoretical and applied studies.