Genesis 6:4

6:4 The Nephilim were on the earth in those days (and also after this) when the sons of God were having sexual relations with the daughters of humankind, who gave birth to their children. They were the mighty heroes of old, the famous men.

Genesis 16:5

16:5 Then Sarai said to Abram, “You have brought this wrong on me! I allowed my servant to have sexual relations with you, but when she realized that she was pregnant, she despised me. May the Lord judge between you and me!”

Genesis 19:8

19:8 Look, I have two daughters who have never had sexual relations with a man. Let me bring them out to you, and you can do to them whatever you please. Only don’t do anything to these men, for they have come under the protection of my roof.”