On a number of occasions in the book the Lord speaks of not making a full end
of Judah (Jeremiah 4:27, Jeremiah 5:10, Jeremiah 5:18, Jeremiah 30:11). Even though the coming judgment is indeed going to be devastating, its final purpose is not to completely destroy Judah, but rather to rid it of unfaithfulness. There is, therefore, in Jeremiah, the idea of a faithful remnant that the Lord will bring about from among his people. This faithful remnant, however, will ultimately come from those who are taken into Exile in Babylon after the invasion. In Jeremiah 6:9, therefore, the remnant of Israel
that is gleaned thoroughly as a vine
is a reference to the nation of Judah, that remained after the destruction, by the Assyrians, of Israel in the north. Judah is the remnant of Israel, they are all that remains of the nation as a whole.1 As this remnant, the Lord’s judgment of them is going to be thorough and complete.
9 Thus says the LORD of hosts: “They shall glean thoroughly as a vine the remnant of Israel; like a grape gatherer pass your hand again over its branches.”