But if you will not hearken to me, to sanctify the sabbath day, and not to carry burdens, and not to bring them in by the gates of Jerusalem on the sabbath day: I will kindle a fire in the gates thereof, and it shall devour the houses of Jerusalem, and it shall not be quenched.
Jeremiah 17:25 Then shall there enter in by the gates of this city kings and princes, sitting upon the throne of David, and riding in chariots and on horses, they and their princes, the men of Juda, and the inhabitants of Jerusalem: and this city shall be inhabited for ever.
Jeremiah 17:26 And they shall come from the cities of Juda, and from the places round about Jerusalem, and from the land of Benjamin, and from the plains, and from the mountains, and from the south, bringing holocausts, and victims, and sacrifices, and frankincense, and they shall bring in an offering into the house of the Lord.
Jeremiah 17:27 But if you will not hearken to me, to sanctify the sabbath day, and not to carry burdens, and not to bring them in by the gates of Jerusalem on the sabbath day: I will kindle a fire in the gates thereof, and it shall devour the houses of Jerusalem, and it shall not be quenched.
The verse centers on "hearken", "sanctify", "sabbath", "carry", "burdens", "bring", "gates", and "jerusalem". It is saying that the verse draws attention to "hearken" and "sanctify", so its meaning should be read from those terms before moving to application.
The prior verse says "And they shall come from the cities...", giving immediate footing for "hearken" and "sanctify". In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "hearken" and "sanctify" with trust shaped by these words, not by a vague optimism outside the passage.