The Book of the Law or Liber AL vel Legis is the central sacred text of Thelema, written down from dictation mostly by Aleister Crowley. Crowley claimed it was dictated to him by a discarnate entity named Aiwass. However, the three chapters are largely written in the first person by the Thelemic deities Nuit, Hadit and Ra-Hoor-Khuit.
The book contains three chapters, each of which was alleged to be written down in one hour in 1904, Cairo, Egypt.