Therefore thus saith the Lord: behold I will visit upon Semeias the Nehelamite, and upon his seed: he shall not have a man to sit in the midst of this people, and he shall not see the good that I will do to my people, saith the Lord: because he hath spoken treason against the Lord.
Jeremiah 29:30 And the word of the Lord came to Jeremiah, saying:
Jeremiah 29:31 Send to all them of the captivity, saying: Thus saith the Lord to Semeias the Nehelamite: Because Semeias hath prophesied to you, and I sent him not: and hath caused you to trust in a lie:
Jeremiah 29:32 Therefore thus saith the Lord: behold I will visit upon Semeias the Nehelamite, and upon his seed: he shall not have a man to sit in the midst of this people, and he shall not see the good that I will do to my people, saith the Lord: because he hath spoken treason against the Lord.
The verse centers on "therefore", "thus", "saith", "lord", "behold", "visit", "upon", and "semeias". It is saying that the verse draws attention to "therefore" and "thus", so its meaning should be read from those terms before moving to application.
The prior verse says "Send to all them of the captivity...", giving immediate footing for "therefore" and "thus". In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "therefore" and "thus" with trust shaped by these words, not by a vague optimism outside the passage.