Genesis 19:34

And it came to pass on the morrow, that the firstborn said unto the younger, Behold, I lay yesternight with my father: let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father.

It came to pass on the next day, that the firstborn said to the younger, "Behold, I lay last night with my father. Let us make him drink wine again, tonight. You go in, and lie with him, that we may preserve our father's seed."

And it came to pass on the morrow, that the first-born said unto the younger, Behold, I lay yesternight with my father: let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father.

And it cometh to pass, on the morrow, that the first-born saith unto the younger, `Lo, I have lain yesterday-night with my father: we cause him to drink wine also to-night, and go thou in, lie with him, and we preserve from our father -- a seed.'

The next day the older daughter said to the younger, “Look, I slept with my father last night. Let us get him drunk with wine again tonight so you can go in and sleep with him and we can preserve our father’s line.”