The Book of Enoch (also 1 Enoch; Ge'ez: መጽሐፈ ሄኖክ maṣḥafa hēnok) is an ancient Hebrew apocalyptic religious text, ascribed by tradition to Enoch, the great-grandfather of Noah. Enoch contains unique material on the origins of demons and giants, why some angels fell from heaven, an explanation of why the Genesis flood was morally necessary, and prophetic exposition of the thousand-year reign of the Messiah.