International Standard Version "If a man takes his brother's wife, it's immoral. He has exposed his brother's nakedness. They'll be childless."
American Standard Version And if a man shall take his brother's wife, it is impurity: he hath uncovered his brother's nakedness; they shall be childless.
Young's Literal Translation And a man who taketh his brother's wife -- it is impurity; the nakedness of his brother he hath uncovered; childless they are.