2. the sons of God saw the daughters of men--By the former is meant the family of Seth, who were professedly religious; by the latter, the descendants of apostate Cain. Mixed marriages between parties of opposite principles and practice were necessarily sources of extensive corruption. The women, religious themselves, would as wives and mothers exert an influence fatal to the existence of religion in their household, and consequently the people of that later age sank to the lowest depravity.

JFB.