The book introduces itself as an oracle about Nineveh and the vision of Nahum the Elkoshite. At once the prophet describes the Lord as a jealous God who takes vengeance on his adversaries, slow to anger and great in power, who will not clear the guilty. His way is in whirlwind and storm; he dries up the sea and the rivers, and mountains, hills and the earth shake before him. No one can stand before his indignation.
In the middle of that picture comes a line of comfort: the Lord is good, a stronghold in the day of trouble, and he knows those who take refuge in him. By contrast, with an overflowing flood he will make an end of the place of his enemies. The prophet asks what they plot against the Lord and answers that he will bring it to a complete end; trouble will not rise a second time. From Nineveh has come one who plotted evil against the Lord and counseled wickedness.
The Lord then speaks to Judah: though the Assyrians are strong and many, they will be cut off and pass away; Judah, afflicted, will be afflicted no more, and the yoke and bonds will be broken. To the king of Assyria he says that his name will have no more offspring, that he will cut off the idols from the temple of his gods and that he is preparing his grave. The chapter ends with a picture of hope: on the mountains are the feet of one who brings good news and announces peace, and Judah is invited to keep her feasts and fulfill her vows, for the wicked will never again pass through her.