So they made their father drink wine that night. And the first-born went in and lay with her father, and he was not aware of it when she lay down or when she arose.
And it came to be on the next day that the first-born said to the younger, “See, I lay with my father last night. Let us make him drink wine tonight as well, and you go in and lie with him, so that we keep the seed of our father.”