Jeremiah 17:27

However, if the people did not observe the Sabbath Day to keep it holy (different from other days), the Lord would consume Jerusalem with unquenchable fire. Notice the prominence in these promises and threats, of: the throne of David, the temple, and the city of Jerusalem. These comprised the basic elements of the national and religious life of the covenant people.

It was not just the fourth commandment that the people were responsible to keep, of course. Jeremiah might have chosen to preach on any of the other nine commandments, and he may have done so at other times. This message is probably representative of many similar sermons that the prophet delivered-calling the people back to obedience to the covenant. It was repentance that would postpone judgment, not just obedience to the fourth commandment. Yet the fourth commandment had special significance. Sabbath observance recognized Yahweh as Creator and Redeemer, and so witnessed against idolatry. It guaranteed God’s people rest, which they could not obtain from idols. And it was one of the unique features of Israel’s religion, because it signified the special covenant relationship between Yahweh and Israel.