The Kabbalah Unveiled is Mathers's 1887 translation of three short, dense texts from the Zohar: the Siphra Dtzenioutha or Book of Concealed Mystery, the Idra Rabba or Greater Holy Assembly, and the Idra Zuta or Lesser Holy Assembly. Because the originals are cryptic, Mathers places his own long introduction in front of them, and most of the page's plain-English account rests on that introduction and on the bracketed commentary he weaves through the text.
His introduction first defines the subject. The Qabalah, he writes, is the esoteric Jewish doctrine, named from a root meaning to receive, because the knowledge was passed down by oral tradition. He sorts the wider literature into headings, the practical, literal, unwritten, and dogmatic Qabalah, and explains the literal techniques of Gematria, Notarikon, and Temura, by which letters are read as numbers and words are permuted, since in Hebrew every word is also a number.
At the center of the doctrine is the Ain Soph, the limitless and unknowable one. Mathers describes three veils of negative existence and says the boundless ocean of light does not proceed from a center but concentrates a center, the first of the ten Sephiroth. These Sephiroth are the numerical emanations of the Deity, running from Kether the Crown down to Malkuth the Kingdom, grouped into three trinities and pictured as the Tree of Life and as the Heavenly Man.
This single pattern is then repeated in a descending scale through four worlds: Atziluth the archetypal world of emanation, Briah the world of creation, Yetzirah the world of formation and angels, and Asiah the world of action and matter. The same introduction explains the partzufim, the divine countenances, in which Kether appears as Macroprosopus the Vast Countenance and the lower Sephiroth gather into Microprosopus the Lesser Countenance, with the King and Queen, Father and Mother, as further faces of the one.
The three translated books themselves are the oldest and most difficult parts of this material. They trace, in highly figurative language, the gradual unfolding of the Deity from negative into positive existence and the creation that comes with it. Read soberly, the work is a historical document of nineteenth-century occultism: a Christian Hermeticist's earnest attempt to open Jewish mystical theology to English readers, governed throughout by the recurring idea that reality is held together by the equilibrium of balanced opposites.