An overview of the book (The Heart and the Change by Al-Asma’i, Study and Compilation) This book is concerned with collecting the texts of the lost book (The Heart and the Change by Al-Asma’i), through extrapolation of the Arabic linguistic heritage, relying on strict standards and controls in selecting these texts, and arranging and organizing them according to a solid scientific approach. To be close to the image that the author left, may God have mercy on him, it is preceded by a detailed study of the author and the author. It is accompanied by technical indexes to serve the reader. Contributing to bringing out a treasure of that heritage, most of which was lost for various reasons. And to revive the legacy of a unique science of linguists who had a great impact on this blessed language.