Genesis 19:33-34

English Standard Version

³³ So they made their father drink wine that night. And the firstborn went in and lay with her father. He did not know when she lay down or when she arose.

³⁴ The next day, the firstborn said to the younger, “Behold, I lay last night with my father. Let us make him drink wine tonight also. Then you go in and lie with him, that we may preserve offspring from our father.”