And these are the words of the letter that the prophet Jeremiah sent from Jerusalem to the residue of the elders of the captivity, and to the priests, and to the prophets, and to all the people whom Nebuchadnezzar had carried away captive from Jerusalem to Babylon
Jeremiah 29:1 And these are the words of the letter that the prophet Jeremiah sent from Jerusalem to the residue of the elders of the captivity, and to the priests, and to the prophets, and to all the people whom Nebuchadnezzar had carried away captive from Jerusalem to Babylon
Jeremiah 29:2 (after that Jeconiah the king, and the queen, and the eunuchs, the princes of Judah and Jerusalem, and the craftsmen, and the smiths, had departed from Jerusalem);
Jeremiah 29:3 by the hand of Elasah the son of Shaphan, and Gemariah the son of Hilkijah (whom Zedekiah king of Judah sent to Babylon, unto Nebuchadnezzar king of Babylon), saying,
The verse centers on "words", "letter", "prophet", "jeremiah", "sent", "jerusalem", "residue", and "elders". It is saying that the verse draws attention to "words" and "letter", so its meaning should be read from those terms before moving to application.
The next verse adds "after that Jeconiah the king and the...", so "words" and "letter" should be read forward into that movement. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "words" and "letter" with trust shaped by these words, not by a vague optimism outside the passage.