Attributed to the Jewish patriarch Moses, the Book of Genesis (composed in the sixth or fifth century BCE) commenced the Hebrew scriptures with the story of God’s creation of the universe, the world, and humankind. Tricked by the serpent, Adam and Eve committed the first sin, for which God expelled them from the Garden of Eden. The wickedness of their descendants so disappointed God that he decided to wipe out his creations with a great deluge. He spared only Noah, whom he instructed to build an ark to preserve himself, his family, and two of every bird and beast to replenish the earth after it had been washed clean by forty days and nights of rain. The role of the Nephilim in this tradition is ambiguous and mysterious. Before the flood, the Book of Genesis hinted that members of God’s heavenly court (“sons of God”) had intermingled with mortal women to produce a race of creatures called “the Nephilim,” a Hebrew word that later Greek and Latin translators rendered as “giants.” These translators took their cue from the Book of Numbers, which related how Moses had sent spies into the land of Canaan, who returned with an ominous report that it was inhabited by the Nephilim: “The land which we have viewed, devoureth its inhabitants: the people, that we beheld, are of a tall stature. There we saw certain monsters of the sons of Enac, of the giant kind: in comparison of whom, we seemed like locusts” (Numbers 13:32–33). The Book of Genesis implied that the sexual commerce between angels and humans that produced the Nephilim was such a terrible transgression that it moved God to sadness and prompted his decision to destroy the world with the great flood.
And after humankind had begun to multiply upon the earth and had produced daughters, the sons of God, seeing that these daughters were beautiful, took wives for themselves from whomever they chose, and God said, “My spirit will not remain in humankind forever, for he is flesh and his days will be one hundred and twenty years.” There were, however, giants on the earth in those days. Indeed, afterwards the sons of God joined with the daughters of men and they bore children. These were the mighty men of old, men of renown. Seeing that there was much wickedness of humankind on the earth and that every thought of their heart turned toward evil all the time, God regretted that he had made humankind on the earth and, moved within by the sadness of his heart, he said, “I will wipe out humankind, whom I have created, from the face of the earth, from human beings even to the animals, from the reptile even to the birds of the sky, for I am sorry that I have made them.”