Jeremiah returns to a metaphor he had spoken on behalf of the Lord in Jeremiah 6:27–30. The Lord will refine them and test them.
Like a tester of metals, maybe the suffering of the Lord’s judgment will remove the unfaithfulness from his people. But much like in Jeremiah 6:27–30, the process of refinement holds very little promise. Because this is a people whose tongue is a deadly arrow, because it speaks deceitfully.
The Lord asks, What else can I do, because of my people?
This last phrase can also be understood as an exclamation and not a question. Either way it expresses the Lord’s exasperation with his people.1
7 C'est pourquoi ainsi parle l'Eternel des armées: Voici je les sonderai, je les éprouverai. Car comment agir à l'égard de la fille de mon peuple?