This passage uses poetry to describe God’s promise to save his people. Their sin had separated them from God (it had broken their relationship with him). God promised to remove that separation and bring them back to himself.
The picture is of a city surrounded by enemy armies. The people inside the city are waiting for news. They hope to hear that their hero has defeated the enemy and won the battle.
Paul uses these words to speak about the good news of the Lord Jesus Christ (Romans 10:15). He shows that this promise is fulfilled in the message about Jesus.