Commentary for Genesis 19:35

וַתַּשְׁקֶ֜יןָ גַּ֣ם בַּלַּ֧יְלָה הַה֛וּא אֶת־אֲבִיהֶ֖ן יָ֑יִן וַתָּ֤קָם הַצְּעִירָה֙ וַתִּשְׁכַּ֣ב עִמּ֔וֹ וְלֹֽא־יָדַ֥ע בְּשִׁכְבָ֖הּ וּבְקֻמָֽהּ׃

And 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.

Radak on Genesis