And the whole valley of dead bodies, and of ashes, and all the country of death, even to the torrent Cedron, and to the corner of the horse gate towards the east, the Holy of the Lord: it shall not be plucked up, and it shall not be destroyed any more for ever.
Jeremiah 31:38 Behold the days come, saith the Lord, that the city shall be built to the Lord from the tower of Hanameel even to the gate of the corner.
Jeremiah 31:39 And the measuring line shall go out farther in his sight upon the hill Gareb: and it shall compass Goatha,
Jeremiah 31:40 And the whole valley of dead bodies, and of ashes, and all the country of death, even to the torrent Cedron, and to the corner of the horse gate towards the east, the Holy of the Lord: it shall not be plucked up, and it shall not be destroyed any more for ever.
The verse centers on "whole", "valley", "dead", "bodies", "ashes", "country", "death", and "even". It is saying that the verse draws attention to "whole" and "valley", so its meaning should be read from those terms before moving to application.
The prior verse says "And the measuring line shall go out...", giving immediate footing for "whole" and "valley". In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "whole" and "valley" with trust shaped by these words, not by a vague optimism outside the passage.