Watchmen would normally alert the people of invasion and call on them to flee to the cities for safety. But here the call is to go up to Zion, to the Lord our God.
It is a call for the Lord’s people to go up to the temple to worship. The call is made “in the hill country of Ephraim which is once again a reference to the northern tribes, but ultimately this speaks of a united people worshipping in Jerusalem. This is a fitting conclusion to the poem of restoration in Jeremiah 31:2–6. The poem has spoken of the Lord once again caring for his people in the wilderness like he did during the Exodus. It speaks of the Lord reversing aspects of judgment experienced during the invasion and exile such as the loss of a resting place, the tearing down of the nation, celebrations silenced, vines and plants uprooted, watchmen announcing invasion and the temple destroyed. The wonderful conclusion of this reversal is the people gathering to worship again in Zion. And why has all of this happened despite the faithlessness of both northern Israel and Judah? Because the Lord has loved them with an everlasting love and continued his faithfulness to them (Jeremiah 31:3)1.
6 For there shall be a day when watchmen will call in the hill country of Ephraim: ‘Arise, and let us go up to Zion, to the LORD our God.’”