This thesis is titled " Al Manhal Assafi Ala Fatih Al Aroodh wal Qawafi" ( i.e. The Pure Spring upon the Instructor of Metrics and Rhymes). The thesis aims at eliciting some of the Omani efforts that serve the Arabic Language and to explicit A'Ssalimi's role in the field of language as to retrieve and edit a book of the Omani Heritage. The theme of the book handles two disciplines of language; metrics and rhyme, written as a long poem with its interpretation. The thesis has been divided into two parts; study and editing. The first part includes two chapters; the author's life and his books, and the book study. The first chapter deals with the author's name and his parentage, education, scholars, students, and authored books. The second chapter handles studying the book in terms of verifying its title as well as its ascription to the author. The chapter also handles introducing the book and its theme, the motive to write it, the author's methodology, the book features, the followed editing approach and comments on the book up to the conclusion. The second part, the edited text, has again two chapters; ----Metrics and-rhyme-disciplines. The text editing approach has been followed in terms of typing the manuscript according to the modern transcription, comparing the two manuscripts, the diacritics of the holy verses and noble speeches of the prophet (Peace Be Upon Him) and the *poems, ascription of texts to their authors, identifying names of people and places, giving titles, clarifying weird vocabulary, and adding comments and indexes.