Genesis 6:1-4

The number of people increased all over the earth, and daughters were born to them. The sons of God saw that the daughters of other humans were beautiful. So they married any woman they chose. Then the LORD said, “My Spirit will not struggle with humans forever, because they are flesh and blood. They will live 120 years.” The Nephilim were on the earth in those days, as well as later, when the sons of God slept with the daughters of other humans and had children by them. These children were famous long ago.