Malachi links rejected offerings to marital treachery, saying the LORD was witness between a man and the wife of his youth Malachi 2:14. The passage says they dealt treacherously even though she was a companion and wife by covenant Malachi 2:14. Because of this, God no longer regards the offering or accepts it with favor Malachi 2:13.
In Malachi 2:13–16 the people complain that Yahweh no longer accepts their offerings, even though they come to the altar with intense emotion. The passage answers that the problem is not the amount of crying but their betrayal in marriage. This unit sits within Malachi’s series of confrontations where the prophet states what the people do, reports their question (“Why?”), and then gives Yahweh’s explanation.
This passage links rejected worship with broken covenant life. The people are emotionally intense at the altar (tears, weeping, sighing), yet Yahweh does not accept their offerings (explicit textual claim).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Malachi 2:14, then read the surrounding section so the answer stays connected to the passage's flow.
14Yet you say, Why? Because Yahweh has been witness between you and the wife of your youth, against whom you have dealt treacherously, though she is your companion, and the wife of your covenant.