Genesis 19:30-38

30 And Lot went up out of Zoar, and dwelled in the mountain, and his two daughters with him; for he feared to dwell in Zoar: and he dwelled in a cave, he and his two daughters.

31 And the firstborn said to the younger, Our father is old, and there is not a man in the earth to come in to us after the manner of all the earth:

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

33 And they made their father drink wine that night: and the firstborn went in, and lay with her father; and he perceived not when she lay down, nor when she arose.

34 And it came to pass on the morrow, that the firstborn said to the younger, Behold, I lay last night with my father: let us make him drink wine this night also; and go you in, and lie with him, that we may preserve seed of our father.

35 And they made their father drink wine that night also: and the younger arose, and lay with him; and he perceived not when she lay down, nor when she arose.

36 Thus were both the daughters of Lot with child by their father.

37 And the first born bore a son, and called his name Moab: the same is the father of the Moabites to this day.

38 And the younger, she also bore a son, and called his name Benammi: the same is the father of the children of Ammon to this day.