Haggai wrote in Hebrew the language of Jesus Christ and the prophets. Isaac Newton held that prophecy in the Ancient Near East spoke with a common language. By this he meant the images in prophetic words. For example a tree in prophecy might be an analogy for a man, as in the case of Nebuchadnezzar in Daniel 4. One thing is certain the Old Testament was written in Hebrew and Aramaic two sister Semitic languages. Jesus Christ and his disciples all spoke Hebrew and Aramaic and grew up in culture of Hebrew and Aramaic. This books gives English speaker access to that text in English letters.