B'resheet (Gen) 6:4-6

The N’filim were on the earth in those days, and also afterwards, when the sons of God came in to the daughters of men, and they bore children to them; these were the ancient heroes, men of renown. (Maftir) ADONAI saw that the people on earth were very wicked, that all the imaginings of their hearts were always of evil only. ADONAI regretted that he had made humankind on the earth; it grieved his heart.