Malachi is the last book of the Old Testament and belongs to the period of Nehemiah. The prophets message is to the priests and the people, charging them with indifference, doubt, and immorality. Malachi tells of the coming day of the Lord and closes the book with a prophecy of John the Baptist.

Malachi 2

2:14 Yet ye say, Wherefore? Because the LORD hath been witness between thee and the wife of thy youth, against whom thou hast dealt treacherously: yet is she thy companion, and the wife of thy covenant.