What does Malachi 2:15 mean?

Prior verses accuse Israel of being unfaithful to each other. Specifically, men are divorcing their wives. Verse 14 explained that this is offensive to God, in part because such vows are made in His presence. Verse 15 clearly describes divorce as a spiritual failure. This claim is repeated and magnified in verse 16. The way in which these men of Israel are divorcing their wives—in order to marry pagan women (Malachi 2:11)—is especially foul. Rather than acting as protectors, these divorcing men are committing acts of spiritual violence against their wives.

Verse 15 is notoriously tricky to translate. Every language contains phrases with meanings not easily seen in the literal words. Examples from English would be phrases such as "raining cats and dogs" or "under the weather." In the case of Hebrew, we don't always have extensive context to help determine meaning. This is reflected in the various translations of this particular verse. While major translations of the Bible are extremely similar in most verses, there are many ways the words of Malachi 2:15 have been interpreted. All are centered around the same basic theme.

Regardless of the exact meaning, there is a clear sense in this verse that God is involved in the concept of marriage. This verse is specifically in the context of men being "faithless" to their wives, through divorce. In contrast, God sees marriage as a joining of spirits, according to His will, which can't be broken without spiritual damage. God has specific purposes for marriage, which are thwarted by divorce.