Nahum was a Jewish prophet and wrote primarily for the Jewish people. While the main subject of his prophesying was Nineveh, his message was for the Jews.
This book claims to be an oracle (1:1, an uplifting and or threatening prophecy). While most of the book threatens Nineveh with destruction, there are also words of comfort for the people of Judah (1:12, 15; 2:2). Nahum revealed that Yahweh would destroy Nineveh as punishment for the Assyrians' cruelty to many nations, including the Northern Kingdom of Israel in 722 B.C. and Judah. This was a comforting message for the remaining Jews who were presently living under Assyria's shadow in Judah. Assyria had destroyed many Judean cities and had even besieged Jerusalem, unsuccessfully, in 701 B.C. The purpose of Nahum's book, then, was to announce Nineveh's fall and thereby comfort the Judean Jews with the assurance that their God was indeed sovereign and just.
"God is a just governor of the nations who will punish wicked Nineveh and restore His own people."5
