Bereshis 19:34-36

Orthodox Jewish Bible

³⁴ And it came to pass on the next day, that the bechirah said unto the younger, Hinei, I lay yesternight with avi. Let us make him drink yayin halailah also; and go thou in, and lie with him, that we may preserve zera by avinu.

³⁵ And they made their av drink yayin balailah also; and the younger arose, and lay with him; and he had da’as not when she lay down, nor when she arose.

³⁶ Thus were both the banot of Lot with child by their av.