This book offers a deep philosophical and linguistic study of the concept of "Dahr" (Time/Eternity) in Arab heritage, tracing its semantic evolution and its dialectical relationship with the concepts of time and space. The author, Muhammad Al-Rahmouni, explores how this concept shaped the structure of ancient Arab thought, both in pre-Islamic poetry and early Islamic texts. The research addresses the problems posed by "Dahr" as a mental construct reflecting a worldview and existence. Through this analysis, the book reveals the dimensions of cultural anthropology that governed the Arab sphere during that era.