Tradition places seraphim in the highest rank in Christian angelology and in the fifth rank of ten in the Jewish angelic hierarchy. A seminal passage in the Book of Isaiah () used the term to describe six-winged beings that fly around the Throne of God crying "holy, holy, holy". This throne scene, with its triple invocation of holiness, profoundly influenced subsequent theology, literature and art. Its influence is frequently seen in works depicting angels, heaven and apotheosis. Seraphim are mentioned as celestial beings in an influential Hellenistic work, the Book of Enoch, and the Book of Revelation.