Thus saith Jehovah of hosts, the God of Israel, concerning Ahab the son of Kolaiah, and concerning Zedekiah the son of Maaseiah, who prophesy a lie unto you in my name: Behold, I will deliver them into the hand of Nebuchadrezzar king of Babylon; and he shall slay them before your eyes;
Jeremiah 29:19 because they have not hearkened to my words, saith Jehovah, wherewith I sent unto them my servants the prophets, rising up early and sending them; but ye would not hear, saith Jehovah.
Jeremiah 29:20 Hear ye therefore the word of Jehovah, all ye of the captivity, whom I have sent away from Jerusalem to Babylon.
Jeremiah 29:21 Thus saith Jehovah of hosts, the God of Israel, concerning Ahab the son of Kolaiah, and concerning Zedekiah the son of Maaseiah, who prophesy a lie unto you in my name: Behold, I will deliver them into the hand of Nebuchadrezzar king of Babylon; and he shall slay them before your eyes;
Jeremiah 29:22 and of them shall be taken up a curse by all the captives of Judah that are in Babylon, saying, Jehovah make thee like Zedekiah and like Ahab, whom the king of Babylon roasted in the fire;
Jeremiah 29:23 because they have wrought folly in Israel, and have committed adultery with their neighbors` wives, and have spoken words in my name falsely, which I commanded them not; and I am he that knoweth, and am witness, saith Jehovah.
The verse centers on "thus", "saith", "jehovah", "hosts", "israel", "concerning", "ahab", and "kolaiah". It is saying that the verse draws attention to "thus" and "saith", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 20's "Hear ye therefore the word of Jehovah..." into verse 22's "and of them shall be taken up...", so "thus" and "saith" belong inside that flow. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "thus" and "saith" with trust shaped by these words, not by a vague optimism outside the passage.