Thus saith the Lord of hosts the God of Israel, to Achab the son of Colias, and to Sedecias the son of Maasias, who prophesy unto you in my name falsely: Behold I will deliver them up into the hands of Nabuchodonosor the king of Babylon: and he shall kill them before your eyes.
Jeremiah 29:19 Because they have not hearkened to my words, saith the Lord: which I sent to them by my servants the prophets, rising by night, and sending: and you have not heard, saith the Lord.
Jeremiah 29:20 Hear ye therefore the word of the Lord, all ye of the captivity, whom I have sent out from Jerusalem to Babylon.
Jeremiah 29:21 Thus saith the Lord of hosts the God of Israel, to Achab the son of Colias, and to Sedecias the son of Maasias, who prophesy unto you in my name falsely: Behold I will deliver them up into the hands of Nabuchodonosor the king of Babylon: and he shall kill them before your eyes.
Jeremiah 29:22 And of them shall be taken up a curse by all the captivity of Juda, that are in Babylon, saying: The Lord make thee like Sedecias, and like Achab, whom the king of Babylon fried in the fire:
Jeremiah 29:23 Because they have acted folly in Israel, and have committed adultery with the wives of their friends, and have spoken lying words in my name, which I commanded them not: I am the judge and the witness, saith the Lord.
The verse centers on "thus", "saith", "lord", "hosts", "israel", "achab", "colias", and "sedecias". 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 the..." 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.