Albert Barnes Commentary Malachi 2:9

"Therefore have I also made you contemptible and base before all the people, according as ye have not kept my ways, but have had respect of persons in the law." — Malachi 2:9 (ASV)

Therefore I have made you contemptible - They had said in their hearts (Malachi 1:7), “The table of the Lord is contemptible.” So God would requite them “measure for measure.” Yet not only so, but in their office as judges, against the repeated injunctions in the law: You shall not respect the person of the poor, nor honor the person of the mighty; in righteousness you shall judge your neighbor (Leviticus 19:15). You shall not respect persons in judgment (Deuteronomy 1:17). You shall not wrest judgment (Deuteronomy 16:19). He says:

You have accepted persons in the law - You have interpreted the law differently for rich and poor, or have put it in force against the poor, not against the rich. It would include actual bribery, but there are many more direct offenses against equal justice. How differently is the same offense against the eighth commandment treated when committed by the poor, who have real temptation to it, and by the rich, who have none but the lust of the eyes!

He condones crows, vexes the simple dove - That contempt which they cast upon God and His law by distorting it out of respect for persons (so that they might gain favor and respect from them, thereby honoring them more than Him and seeking to please them more than Him) He will cast back on them, making them contemptible even in the eyes of those from whom they thought by that means to find respect.