Genesis 19:34-38

34The next day the older daughter said to the younger, “Look, I slept with my father last night. Let us get him drunk with wine again tonight so you can go in and sleep with him and we can preserve our father’s line.”

35So again that night they got their father drunk with wine, and the younger daughter went in and slept with him; he was not aware when she lay down or when she got up.

36Thus both of Lot’s daughters became pregnant by their father. 37The older daughter gave birth to a son and named him Moab.1 He is the father of the Moabites of today. 38The younger daughter also gave birth to a son, and she named him Ben-ammi.2 He is the father of the Ammonites of today.