Deuteronomy 22:29-30

Young's Literal Translation

²⁹ then hath the man who is lying with her given to the father of the damsel fifty silverlings, and to him she is for a wife; because that he hath humbled her, he is not able to send her away all his days.

³⁰ `A man doth not take his father's wife, nor uncover his father's skirt.