Genesis 19:30-38

³⁰Now Lot went up out of Zo'ar, and dwelt in the hills with his two daughters, for he was afraid to dwell in Zo'ar; so he dwelt in a cave with his two daughters. ³¹And the first-born said to the younger, "Our father is old, and there is not a man on earth to come in to us after the manner of all the earth. ³²Come, let us make our father drink wine, and we will lie with him, that we may preserve offspring through our father." ³³So they made their father drink wine that night; and the first-born went in, and lay with her father; he did not know when she lay down or when she arose. ³⁴And on the next day, the first-born said to the younger, "Behold, I lay last night with my father; let us make him drink wine tonight also; then you go in and lie with him, that we may preserve offspring through our father." ³⁵So 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. ³⁶Thus both the daughters of Lot were with child by their father. ³⁷The first-born bore a son, and called his name Moab; he is the father of the Moabites to this day. ³⁸The younger also bore a son, and called his name Ben-ammi; he is the father of the Ammonites to this day.