Genesis 19:33-35

New Revised Standard Version, Anglicised

³³ So they made their father drink wine that night; and the firstborn went in, and lay with her father; he did not know when she lay down or when she rose. ³⁴ On the next day, the firstborn said to the younger, ‘Look, I lay last night with my father; let us make him drink wine tonight also; then you go in and lie with him, so that we may preserve offspring through our father.’ ³⁵ So they made their father drink wine that night also; and the younger rose, and lay with him; and he did not know when she lay down or when she rose.