So that night they got their father drunk with wine, and the firstborn went in and slept with her father; he was not aware when she lay down or when she got up.
KJV
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.
ASV
And they made their father drink wine that night: and the first-born went in, and lay with her father; and he knew not when she lay down, nor when she arose.