# Zedekiah king of Judah had imprisoned him

It might be best to translate that other people helped Zedekiah do this.

# had imprisoned him

Here "him" refers to Jeremiah.

# Why do you prophesy and say

"It is wrong for you to continue prophesying and saying"

# I am about to give over this city into the hand of the king of Babylon

"I am about to put this city under the control of the king of Babylon". It might be best to translate that other people would help the king of Babylon.