A book in the library of Joseph Curwen.

The Zohar is also know as the "Sepher Hazzohar." It is one of the two most important cabalist work (the other is the "Sepher Yetzirah," The Book of Formation). Zohar means 'Brightness,' as in Daniel 12:3. While much of the doctrine is probably derived from the Gnostics who were in turn influenced by Pythagoras, it is traditionally thought that its fundamental doctrines go as far back as Abraham and, there can be no doubt that it represents a very early stage of Jewish mysticism. While portions of the works come from somewhere between the second and sixth century A.D., it was compiled around 1275 by the Spanish scholar Moses de Leon (fl. 13th century), who ascribed it to Rabbi Simeon ben Yohai (fl. 2nd century). The Zohar is also sometimes called the Book of Spendor. Its importance is that is one of the oldes systems of mystical thought in the world and has been considered by many as the key to all the mysteries of the universe.

[The Case of Charles Dexter Ward - H.P.L.]