Genesis 6:2

the sons of the nobles. Another explanation: בְּנֵי הָאֱלֹהִים are the princes who go as messengers of the Omnipresent. They too mingled with them. Every אֱלֹהִים in Scripture is an expression of authority, and the following proves it (Exod. 4:16): “And you shall be to him as a lord (לֵאלֹהִים)”; (Eodus 7:1): “See, I have made you a lord (אֶלֹהִים).”

and the sons of the great saw that the daughters of men were beautiful, and painted, and curled, walking with revelation of the flesh, and with imaginations of wickedness; that they took them wives of all who pleased them.

BNEI HA’ELOHIM. The sons of princes and rulers. This is the language of Rashi, and so it is in Bereshith Rabbah. If so, Scripture relates that the judges whose duty it was to administer justice among them committed open violence without anyone interfering.

‘KI’ (WHEN) THEY WERE FAIR. [The meaning of the word ki here] is the same as in the verses: ‘Ki’ (when) thou seest the ass of him that hateth thee; ‘ki’ (when) a bird’s nest chance to be before thee. When the daughters of men were fair, they would take them forcibly as wives for themselves. Thus Scripture tells of the violence and mentions further, whomsoever they chose, in order to include those who were married to others. Scripture, however, did not mention the prohibition concerning them clearly, and the punishment decreed upon them was only because of the violence, because this is a reasoned concept and does not require the Torah to prohibit it.

ויראו בני האלוהים, the sons of the judges, the elite of the species who are here referred to as אלוהים, just as in Exodus 22,27 אלוהים לא תקלל, “you must not curse a judge.” There are numerous similar examples in the Torah of the attribute אלוהים being applied to morally high ranking human beings. Onkelos also translates it in this vein when he speaks of בני רברביא. The explanations offered that the Torah refers to Uzza and Uzael are very far fetched. (compare Torah shleymah on this verse). [The two aforementioned are supposed to have been angels who had voted against the creation of man and who belittled man’s effort to conquer the evil urge. They were supposedly punished by being consigned to earth to experience life on earth by themselves. Instead of proving their superiority, they were the first to succumb to the allurement of physically attractive females. Their request to return to the celestial regions was denied by G’d. Ed.]
According to Bereshit Rabbah 26,5 Rabbi Shimon ben Yochai cursed anyone who translated the words בני האלוהים as “the sons of G’d.” He added that when the elite of the people are themselves guilty of the sins they want the common man to refrain from, their efforts are doomed to start with. Another reason offered why these people were referred to as בני האלוהים, (according to both Rabbi Chaninah and Rabbi Shimon ben Lakish, is that these were the people enjoying carefree long lives, free from sickness and other impediments. [This may have given them the illusion of being able to get away with whatever they felt like doing. Ed.] Rav Hunna, quoting Rabbi Yossi, says that these people were granted such long lives in order to enable them to study the sky, observe the orbits of the stars and make calculations resulting in our calendar.