Why must Jeremiah declare in Judah and Jerusalem that the trumpet must be blown, and the people must go into the fortified cities?
In the previous section (Jeremiah 3:1–4:4) the Lord called on the people of Judah to repent of their unfaithfulness and to return to him. The section ended, however, with a sobering warning of judgement (Jeremiah 4:4). Clearly, the repentance Jeremiah spoke of did not come about and so the following section describes the judgement in more detail. The prospect of judgement has already been mentioned in the opening chapters (Jeremiah 1:13–16; Jeremiah 2:35).
Much like the previous section, this section appears to be made up of oracles and visions from different periods of Jeremiah’s ministry, but they have been carefully collected and arranged into a masterful prophecy of judgment. In particular, they focus on the rising prospect of judgment from the north coming in the form of the Babylonian army, which finally arrived in 597/587 BC. But the exact identity of the threat is not Jeremiah’s main concern in this section. His main concern is to deliver his prophecy of impending judgment and destruction.1 His hope is still that Judah will turn to the Lord in repentance.
The section opens with a series of short cries as a messenger in Jerusalem and Judah raises the alarm of an approaching enemy from the north. This same type of cry is heard from other prophets at times of crisis for Israel (Hosea 5:8; Joel 2:1; Nahum 2:1).2
The call is urgent. The enemy is so close that the people are to go into the fortified cities.
They must withdraw to safety behind the walls of the cities and take up a defensive position. The shophar is a blowing horn or trumpet
that was used to sound the alarm of an approaching enemy. In this case it must be blown "through the land,” probably because the invader would move so quickly.3
5 Declare in Judah, and proclaim in Jerusalem, and say, “Blow the trumpet through the land; cry aloud and say, ‘Assemble, and let us go into the fortified cities!’