Malachi 2:14-15

But you say, “Why does he not?” Because the LORD was witness between you and the wife of your youth, to whom you have been faithless, though she is your companion and your wife by covenant. Did he not make them one, with a portion of the Spirit in their union? And what was the one God seeking? Godly offspring. So guard yourselves in your spirit, and let none of you be faithless to the wife of your youth.