Genesis 6:1-4

And it cometh to pass that mankind have begun to multiply on the face of the ground, and daughters have been born to them, and sons of God see the daughters of men that they [are] fair, and they take to themselves women of all whom they have chosen. And JEHOVAH saith, ‘My Spirit doth not strive in man — to the age; in their erring they [are] flesh:’ and his days have been an hundred and twenty years. The fallen ones were in the earth in those days, and even afterwards when sons of God come in unto daughters of men, and they have borne to them — they [are] the heroes, who, from of old, [are] the men of name.