Malachi 2:14

14 You ask, “Why?” It is because the LORD is the witness between you and the wife of your youth. You have been unfaithful to her, though she is your partner, the wife of your marriage covenant.

Read Malachi 2:14 Using Other Translations

Yet ye say, Wherefore? Because the LORD hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously: yet is she thy companion, and the wife of thy covenant.
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.
You cry out, “Why doesn’t the LORD accept my worship?” I’ll tell you why! Because the LORD witnessed the vows you and your wife made when you were young. But you have been unfaithful to her, though she remained your faithful partner, the wife of your marriage vows.