Genesis

³³And they made their father drink wine that night: and the firstborn went in, and lay with her father; and he knew not when she lay down, nor when she arose. ³⁴And it came to pass on the morrow, that the firstborn said unto the younger, Behold, I lay yesternight with my father: let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father. ³⁵And they made their father drink wine that night also: and the younger arose, and lay with him; and he knew not when she lay down, nor when she arose. ³⁶Thus were both the daughters of Lot with child by their father. ³⁷And the firstborn bare a son, and called his name Moab: the same is the father of the Moabites unto this day. ³⁸And the younger, she also bare a son, and called his name Ben-ammi: the same is the father of the children of Ammon unto this day.