Genesis 19:31-36

31Later the older daughter said to the younger, “Our father is old, and there is no man anywhere nearby to have sexual relations with us, according to the way of all the world.

32Come, let’s make our father drunk with wine so we can have sexual relations with him and preserve our family line through our father.”

33So that night they made their father drunk with wine, and the older daughter came and had sexual relations with her father. But he was not aware that she had sexual relations with him and then got up.

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.