Genesis 6:4 in the King James Version
There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Context
3 The LORD said, “My Spirit will not strive with man forever, because he also is flesh; so his days will be one hundred twenty years.”
4 The Nephilim were on the earth in those days, and also after that, when God’s sons came in to men’s daughters and had children with them. Those were the mighty men who were of old, men of renown.
5 The LORD saw that the wickedness of man was great on the earth, and that every imagination of the thoughts of man’s heart was continually only evil.