Genesis 6:2
1 When humankind began to multiply on the face of the earth, and daughters were born to them, 2 the sons of God saw that the daughters of humankind were beautiful. Thus they took wives for themselves from any they chose. 3 So the Lord said, “My Spirit will not remain in humankind indefinitely, since they are mortal. They will remain for 120 more years.” 4 The Nephilim were on the earth in those days (and also after this) when the sons of God would sleep with the daughters of humankind, who gave birth to their children. They were the mighty heroes of old, the famous men.
1 Enoch 7:1
1 And all the others together with them took unto themselves wives, and each chose for himself one, and they began to go in unto them and to defile themselves with them, and they taught them charms and enchantments, and the cutting of roots, and made them acquainted with plants. 2 And they became pregnant, and they bare great giants, whose height was three thousand ells: 3 Who consumed all the acquisitions of men. And when men could no longer sustain them,
Notes and References
"... In the Book of the Watchers, the sexual consorting of the Watchers with the 'daughters of men' is portrayed as a deliberate act of rebellion against Yahweh. However, in Genesis 6:4, the intercourse of the 'sons of God' with the 'daughters of men' appears to have been presented in a morally neutral manner. In Genesis 6:3-6, man is clearly responsible fur evil in the world. The Genesis 6:1-4 narrative does not connect the angels or their offspring with wickedness, corruption, or violence. The Nephilim are also descnbed in morally unbiased terms in Genesis. Conversely, the Book ofWatchers indicates that the actions of the fallen angels and the giant offspring that resulted were viewed as the source of evil in the pre-diluvian world. Genesis 6:7 suggests that God intended to obliterate His creation because of the sins of humankind. On the other hand, 1 Enoch 7:1-6 suggests that God's anger was caused by the malevolent actions of the Watchers and the Nephilim ..."
Dingman, Terry William The Influence Of The Angelology Of 1 Enoch On Judaism In The Second Temple Period (p. 252) UIniversity of South Africa, 2002