Kitāb Hirmis al-ḥakīm (The book of Hermes the Wise) is a text on invocations, magical incantations, and medicinal draughts used for the treatment of maladies. The purported author, Hermes Trismegistus (Thrice-great Hermes), was a legendary figure in the classical Greek, Roman, and Islamic worlds, to whom a large corpus of writing was attributed. The book is organized according to the Arabic letters arranged in the abjad system (alif, bā’, jīm, dāl and so forth). The discussion for each letter begins with a diagnosis of an adult male who is the sāḥib (companion) of the letter, and proceeds to a prescribed therapy involving incantations (occasionally of religious texts such as the throne verse of the Qur’an), as well as botanical preparations and other medicinal compounds. The text then proceeds to discuss the case of a boy, an adult female, and a girl described in a similarly esoteric fashion as the companion of the letter in question, while prescribing the appropriate therapy for each. The mythology of Hermes Trismegistus took various forms. An early Islamic account is that of Abu Sahl al-Fadl ibn Nawbakht (died circa 815), astrologer to several of the early Abbasid caliphs. Abu Sahl is quoted by later authors as identifying Hermes as a resident of Babylon, driven away to Egypt at the fall of the Persian Empire to Alexander. Such an account would have served well to place the origin of Hermes’ astrology in the territory of the Persian Empire, and thus within the purview of Abu Sahl—an astrologer of Persian heritage working at the caliphal court in Baghdad. Modern researchers point out the varied nature of the individual works in the vast Hermetic corpus in the Islamic world, written at different times, with different purposes and aims, united only in their claims of authorship in reference to the legendary Hermes. This manuscript, in naskh script and black ink with frequent scribal errors, is dated to 830 AH (1426‒27 AD), although the scholar A.Z. Iskander identifies the manuscript as a 20th century copy of an earlier manuscript.