Genesis 6:2
That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose.
Cross-reference
Genesis 3:6 shows Eve seeing the fruit was desirable — both passages follow the pattern: seeing that something is good/beautiful leads to taking what should not be taken.
Genesis 39:7 describes Potiphar's wife looking at Joseph with desire — a direct parallel: seeing someone's beauty ignites lustful pursuit, mirroring the sons of God's gaze.
In Genesis 38:2, Judah sees a Canaanite woman and takes her as wife — directly echoing the see-and-take-marriage pattern of the main verse.
In Genesis 28:1, Isaac charges Jacob not to marry a Canaanite woman — the same marriage-boundary concern seen in these pre-flood unions.
Some identify the 'sons of God' with the Sethite line that 'began to call on the LORD' in Genesis 4:26, linking worship with godly descent.
2 Samuel 11:2 shows David seeing Bathsheba and noting she was beautiful — the same 'saw...beautiful...took' pattern of visual desire leading to sexual sin.
Job 31:1 records Job's covenant with his eyes not to gaze lustfully — a direct contrast: Job guards against the very 'seeing and desiring' that the sons of God indulged.
Psalm 82:6 says 'you are sons of the Most High' — closely paralleling 'sons of God,' supporting the divine beings interpretation.
2 Peter 2:14 warns of false teachers with eyes full of adultery who entice the unstable — a strong parallel to seeing beauty and pursuing sexual sin unchecked.
Deuteronomy 21:11 describes a man seeing a captive woman, desiring her beauty, and taking her as wife — a law regulating the exact see-and-take dynamic here.
In Judges 14:1, Samson sees a Philistine woman and demands to take her — the see-then-take pattern of a strong figure pursuing a woman based on appearance.
1 Kings 11:1 describes Solomon taking many foreign wives — mass intermarriage echoing the 'sons of God' taking wives 'of all which they chose.'
Matthew 24:38 directly references this pre-flood era: people were 'marrying and giving in marriage' right up until the flood came.
In 1 John 2:16, the lust of the flesh and eyes directly addresses the physical desire seen in the sons of God's attraction to beauty.
Malachi 2:11 condemns 'marrying the daughter of a foreign god,' echoing the theme of improper unions between God's people and outsiders.