The manuscript comprises a brief Introduction, the Sacred Books, and an Appendix. In the first, the compiler indicates the source of his information and gives a sketch of the life of Sei? 'Ad, the chief saint of the Yezidis. The Sacred Books comprise Kitb al-Jilwah (Book of Revelation), and Ma??af Rs (Black Book)--so named because in it mention made of the descent of the Lord upon the Black Mountain. Al Jilwah is ascribed to Sei? 'Ad himself, and would accordingly date from the twelfth century A. D. It is divided into a brief introduction and five short chapters. In each, 'Ad is represented as the speaker. In the Preface the Sei? says that he existed with Melek ?'s before the creation of the world, and that he was sent by his god ?'s to instruct the Yezidi sect in truth.