Liber AL vel Legis (), commonly known as The Book of the Law, is the central sacred text of Thelema. Aleister Crowley said that it was dictated to him by a beyond-human being who called himself 'Aiwass'. Rose Edith Kelly, Crowley's wife, wrote two phrases in the manuscript. The three chapters of the book are spoken by the deities Nuit, Hadit, and Ra-Hoor-Khuit. Through the reception of the Book, Crowley proclaimed the arrival of a new stage in the spiritual evolution of humanity, to be known as the "Æon of Horus". The primary precept of this new aeon is the charge, "Do what thou wilt shall be the whole of the Law." The book contains three chapters, each of which was alleged to be written down in one hour, beginning at noon, on 8 April, 9 April, and 10 April in Cairo, Egypt, in the year 1904. Crowley says that the author was an entity named Aiwass, whom he later referred to as his personal Holy Guardian Angel. Biographer Lawrence Sutin quotes private diaries that fit this story and writes that "if ever Crowley uttered the truth of his relation to the Book," his public account accurately describes what he remembered on this point. Crowley himself wrote "Certain very serious questions have arisen with regard to the method by which this Book was obtained. I do not refer to those doubts—real or pretended—which hostility engenders, for all such are dispelled by study of the text; no forger could have prepared so complex a set of numerical and literal puzzles[...]" The book is often referred to simply as Liber AL, Liber Legis or just AL, though technically the latter two refer only to the manuscript. Structure and title The technical title of the book is Liber AL vel Legis, sub figura CCXX, as delivered by XCIII=418 to DCLXVI, although this title never occurs in the Book itself, which refers to itself as "the Book of the Law" and "the threefold Book of Law" (chapters 1:35, 3:75). CCXX is 220 in Roman figures, representing The Tree of Life (10 numbers times 22 paths), and is the number of verses of the Book in typescript. XCIII is 93, the enumeration of both "The word of the law" Thelema and Aiwass. DCLXVI is 666, the number of Crowley as Great Beast both as Adept and Magus. This is a way of saying that the