The book of characteristics is one of the most famous books written in the jurisprudence of language and its philosophy, and the secrets and facts of Arabic, written by Ibn Jenni, who says in the introduction to his book on his book: "A book that I have still remains on the excess of the situation, and the time of time, observed it, Akkaf the thought on it, attracted opinion and narration To him and to find that I find a neglected that he gave him, or a defect that raised him with his work, and the time is increasing with his tight club ..And all the evidence for what this honorable language deposited ... ». The book is the most important books of Ibn Jenni, as the Arabic language hernia is an intercession.