The last of the writing prophets, whose short book is built as a series of disputes: God states a case, the people answer back, and the prophet responds. He confronts priests offering blind and lame animals, men divorcing the wives of their youth, and a nation robbing God in tithes — while promising that the messenger will prepare the way and the sun of righteousness will rise with healing in its wings. The Old Testament closes with his promise of Elijah's return.
“Behold, I send my messenger, and he will prepare the way before me; and the Lord, whom you seek, will suddenly come to his temple; and the messenger of the covenant, whom you desire, behold, he comes!” says Yahweh of Armies.