Genesis 19:34-36

International Standard Version

³⁴ The next day the firstborn told the younger one, “Look! I had sex with my father last night. Let’s make him drink wine tonight again as well. Then you have sex with him, too. That way we’ll preserve our father’s lineage.” ³⁵ So they made their father drink wine that night as well, so he was not aware when she lay down or when she got up.

³⁶ That’s how both of Lot’s daughters became pregnant by their father.