Malachi 2:14

2:14 Yet you ask, “Why?” The Lord is testifying against you on behalf of the wife you married when you were young,19 to whom you have become unfaithful even though she is your companion and wife by law.20

19	tn Heb “the Lord is a witness between you and [between] the wife of your youth.”
20	sn Though there is no explicit reference to marriage vows in the OT (but see Job 7:13; Prov 2:17; Ezek 16:8), the term law (Heb “covenant”) here asserts that such vows or agreements must have existed. References to divorce documents (e.g., Deut 24:1–3; Jer 3:8) also presuppose the existence of marriage documents.