Jeremiah 17:25
Then shall there enter into the gates of this city kings and princes sitting upon the throne of David, riding in chariots and on horses, they, and their princes, the men of Judah, and the inhabitants of Jerusalem: and this city shall remain for ever.
If Jerusalem's people obeyed God by keeping the Sabbath holy and doing no work on it, the promised blessing would follow. Then kings and princes of David's line sitting upon David's throne would enter the gates of the city, together with their princes, the men of Judah, and the inhabitants of Jerusalem. In that obedience the city would endure and remain forever, its lasting prosperity made conditional on faithful obedience.
That permanence required continued faithfulness and allegiance to God. Jerusalem's long history of divine favor did not make its future unconditional. The people's rebellion put the promise at risk, and as a result Jerusalem did not stand forever.