The purpose of this study is to present a review of the book, " Al Taqyeed" which is one of the valuable treasures in the Omani grammar library. This book is considered as one of the rich publications which deeply and excessively illustrates Arabic grammar, morphology and punctuation in ten chapters. This study is divided into two parts: Theory and investigatory. The first part is divided into three chapters. The first chapter provides a clear description of Al Ruqaishi name, pedigree, nickname and the political, social, scientific era in which he lived as well as his scientific biography and his death. Chapter two presents a review of the book, including the author's approach, his vision of quotation, his grammar doctrine, his position in front of some grammarians, references, some critiques, and the study results. Chapter three describes the manuscript focusing on the book documentation, the description of the certified copies and the investigative method. The second part covers the first two chapters mentioned above in investigative way.