Genesis 6:1-4

Young's Literal Translation

6 And it cometh to pass that mankind have begun to multiply on the face of the ground, and daughters have been born to them,

² 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.

³ 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.

⁴ 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.