Genesis 19:30-35

30Then Lot went up out of Zoar and dwelt in the mountains, and his two daughters were with him; for he was afraid to dwell in Zoar. And he and his two daughters dwelt in a cave.

31Now the firstborn said to the younger, “Our father is old, and there is no man on the earth to come in to us as is the custom of all the earth.

32Come, let us make our father drink wine, and we will lie with him, that we may preserve the lineage of our father.”

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

34It happened on the next day that the firstborn said to the younger, “Indeed I lay with my father last night; let us make him drink wine tonight also, and you go in and lie with him, that we may preserve the lineage of our father.”

35Then they made their father drink wine that night also. And the younger arose and lay with him, and he did not know when she lay down or when she arose.