This is an idiom that is used to introduce something that God told his prophets or his people. Alternate translation: "God spoke this message ... and he said" or "God spoke these words ... and he said" (See: [[rc://en/ta/man/translate/figs-idiom]])
The expression "man of God" is a respectful way of referring to a prophet of Yahweh. Alternate translation: "the man who belongs to God" or "the prophet of God"