Both Good News Translation (“God’s people ask”) and Die Bibel im heutigen Deutsch (“The people of Judah say”) indicate that a new speaker is introduced in this verse.
The first part of this verse is similar to 4.5b (“Assemble, and let us go into the fortified cities!”).
The rhetorical question Why do we sit still? may need to be expressed as an affirmative statement, such as “We shouldn’t be sitting still” or “We have to get moving.”
Gather together is probably not to be understood as suggesting a formal gathering of the people. Rather it is to be combined with let us go to form a single thought: “Come on, we will run…” (Good News Translation; similarly Die Bibel im heutigen Deutsch).
The fortified cities, as elsewhere, can be “the cities protected by walls” or “the cities fortified against enemies.”
And perish there adds a dimension of fatalism which is not in the 4.5 passage. In this context perish has the meaning of “die” (Good News Translation): “we won’t even be able to save our lives by doing that” (Die Bibel im heutigen Deutsch); “and there await death” (Bible en français courant).
For LORD our God, refer to 2.17.
Doomed us to perish (Good News Translation “condemned us to die”) is explained by and has given us poisoned water to drink. The use of and to link a qualifying statement with what is before it is quite common in Hebrew. However, it will be more natural in many languages to say something like “he has condemned us to die by giving us poisoned water to drink” or “he has decreed we shall die, and therefore has given us poisoned water to drink.”
Sinned against the LORD is often more natural if the LORD is replaced by “him” (Good News Translation). Even if this is not done, it should be made clear in translation that the LORD is the same person as the LORD our God two lines above.
Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on Jeremiah. (UBS Helps for Translators). New York: UBS, 2003. For this and other handbooks for translators see here .
