Rabbi said: The angels who fell from their holy place in heaven saw the daughters of the generations of Cain walking about naked, with their eyes painted like harlots, and they went astray after them, and took wives from amongst them, as it is said, "And the sons of Elohim saw the daughters of men that they were fair; and they took them wives of all that they chose" (Gen. 6:2).
Rabbi Joshua said: The angels are flaming fire, as it is said, "His servants are a flaming fire" (Ps. 104:4), and fire came with the coition of flesh and blood, but did not burn the body; but when they fell from heaven, from their holy place, their strength and stature (became) like that of the sons of men, and their frame was (made of) clods of dust, as it is said, "My flesh is clothed with worms and clods of dust" (Job 7:5).