This study examines the concepts and mechanisms of textual cohesion within the foundational linguistic work of Sibawayh, Al-Kitab, comparing his analytical framework with modern text linguistics, particularly the model established by M.A.K. Halliday and Ruqaiya Hasan. The paper investigates how Sibawayh addressed the formal and semantic interconnections that govern discourse coherence. By analyzing core textual operations such as reference, substitution, deletion (ellipsis), conjunction, and lexical cohesion (collocation), this research demonstrates that Sibawayh’s analytical methodology anticipated key tenets of contemporary discourse analysis, generative-transformational rules, and context-dependent semantics, strictly situating textual cohesion within the structural integrity of the text itself.