And it came to pass when the children of men began to
multiply on the face of the earth and daughters were born unto
them, that the angels of El saw them on a certain year of this
jubilee, that they were beautiful to look upon; and they took
themselves wives of all whom they chose, and they bare unto them
sons and they were giants.
And lawlessness increased on the earth and all flesh corrupted its way, alike men and cattle and beasts and birds and everything that walks on the earth -all of them corrupted in their ways and orders, and they began to devour each other, and lawlessness increased on the earth and every imagination of the thoughts of all men was thus evil continually.
And El looked upon the earth, and behold it was corrupt, and all flesh had corrupted its orders, and all that were upon the earth had wrought all manner of evil before His eyes.
And He said that He would destroy man and all flesh upon the face of the earth which He had created.
But Noe found grace before the eyes of the Lord.
And against the angels whom He had sent upon the earth, He was exceedingly wroth, and He gave commandment to root them out of all their dominion, and He bade us to bind them in the depths of the earth, and behold they are bound in the midst of them, and are kept separate.
And against their sons went forth a command from before His face that they should be smitten with the sword, and be removed from under heaven...
Jubilees Chapter 5