הנפלים היו בארץ בימים ההם וגם אחרי כן אשר יבאו בני האלקים אל בנות האדם וילדו להם המה הגברים אשר מעולם אנשי השם
The giants were on the earth in those days and also after that, when the sons of the godly line had already come to the daughters of men, who bore them children. These are the heroes from a distant past, the men of renown.
—
In the Kayinite line, in which the spiritual element had become extinct, physical development assumed gigantic dimensions. Had the interbreeding of the two lines succeeded, the spiritual element of the father would have overcome the physical element of the mother. Spiritual giants would have been produced. The work of the spirit requires physical strength. (The physical would have served as a handmaiden to the spiritual. This is a concept that is discussed often. GS)
This did not happen. The union resulted in the physical subordinating the spiritual. The result was that even though these were the children of בני ,האלקים they were rebellious and sacrilegious.
(So that the verse reads… and even after that, when the sons of the godly line had already come to the daughters of men, [and hoped that their spiritual element would be passed on through their children] they bore them children. who were נפילים – predominantly physical… GS)
Beraishis 6:4
pages 166-167
