Charles Ellicott Commentary Malachi 2:14

"Yet ye say, Wherefore? Because Jehovah hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously, though she is thy companion, and the wife of thy covenant." — Malachi 2:14 (ASV)

Again, with supercilious surprise they ask, “Why?”

Witness. Compare Genesis 31:49-50: “The LORD watch between me and thee, when we are absent one from another. If thou shalt afflict my daughters, or if thou shalt take other wives beside my daughters, no man is with us; see, God is witness betwixt me and thee.” If people would seriously consider the meaning of this verse of Genesis, they would not be so fond of putting MIZPAH on their rings, for it denotes a strong suspicion as to the fidelity of the other party.