Genesis 19:34

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.'