A seraph (the burning one") is a type of celestial or heavenly being originating in Ancient Judaism. The term plays a role in subsequent Judaism, Christianity, and Islam. The singular "seraph" is a back-formation from the Hebrew plural-form "seraphim", whereas in Hebrew the singular is "saraph".
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 (Isaiah 6:1–8) 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 (a formula that came to be known as the Trisagion), 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.