“Do What Thou Wilt” is a phrase from the Book of the Law written by Aleister Crowley in 1904, in 3 one-hour periods between April 8-10. He claims to have been aided by an entity named Aiwass.
Courtesy of Wikipedia
According to Crowley, the story began on 16 March 1904, when he tried to “shew the Sylphs” by means of a ritual to his wife, Rose Kelly. Although she could see nothing, she did seem to enter into a light trance and repeatedly said, “They’re waiting for you!” Since Rose had no interest in magic or mysticism, he took little interest. However, on the 18th, after invoking Thoth (the god of knowledge), she mentioned Horusby name as the one waiting for him. Crowley, still skeptical, asked her numerous questions about Horus, which she answered accurately — without having any prior study of the subject. Crowley also gives a different chronology, in which an invocation of Horus preceded the questioning. Lawrence Sutin says this ritual described Horus in detail, and could have given Rose the answers to her husband’s questions.The final proof was Rose’s identification of Horus in the stele of Ankh-ef-en-Khonsu, then housed in the Bulaq Museum (inventory number 666) but now in the Egyptian Museum of Cairo (number A 9422). The stela was subsequently known to practitioners of Thelema as the “Stele of Revealing.”
On 20 March, Crowley invoked Horus, “with great success.” Between 23 March and 8 April, Crowley had the hieroglyphs on the stele translated. Also, Rose revealed that her “informant” was not Horus himself, but his messenger, Aiwass. Finally, on 7 April, Rose gave Crowley his instructions—for three days he was to enter the “temple” and write down what he heard between noon and 1:00 p.m.