Genesis 19:34-38

34So in the morning the older daughter said to the younger, “Since I had sexual relations with my father last night, let’s make him drunk again tonight. Then you go and have sexual relations with him so we can preserve our family line through our father.”

35So they made their father drunk that night as well, and the younger one came and had sexual relations with him. But he was not aware that she had sexual relations with him and then got up.

36In this way both of Lot’s daughters became pregnant by their father.

37The older daughter gave birth to a son and named him Moab. He is the ancestor of the Moabites of today.

38The younger daughter also gave birth to a son and named him Ben-Ammi. He is the ancestor of the Ammonites of today.