Genesis 6:1-4 ▼

1 Now after the population of human beings had increased throughout the earth, and daughters had been born to them,

2 some divine beings noticed how attractive human women were, so they took wives for themselves from a selection that pleased them.

3 So the LORD said, |My Spirit won't remain with human beings forever, because they're truly mortal. Their lifespan will be 120 years.|

4 The Nephilim were on the earth at that time (and also immediately afterward), when those divine beings were having sexual relations with those human women, who gave birth to children for them. These children became the heroes and legendary figures of ancient times.