There are several theories concerning the identity of the sons of God (B'nai HaElohim, בני האלהים, contrasted with "daughters of men", Benoth Adam, הבנות של אדם) identified in the Book of Genesis. When men began to increase in number on the earth and daughters were born to them, the sons of God saw that the daughters of men were beautiful, and they married any of them they chose. (Genesis 6:1-6:2)