Dora Bas Rivka Silver O'H
Yehoyakim's son Yehoyachin was removed from office by Nebuchadnezzar and replaced with Tzidkiyahu, fulfilling the prophecy of the previous chapter. However, in Yehoyakim's day, the people were willing to follow Jeremiah, but the king stopped them. In Tzidkiyahu's day, neither the king nor the people were willing to heed the prophet.
Tzidkiyahu sent messengers to ask Jeremiah to pray to G-d for the nation against Nebuchadnezzar. (Jeremiah was free at this time and not in prison.) The Egyptian army was coming to assist and the Chaldean forces withdrew. (Egypt was an ally of Judah; the Chaldeans were with Babylonia.) G-d told Jeremiah to tell the king's delegation that the Egyptian army was returning home. The Chaldean forces would return and burn the city. Even if the army of Judah struck every Chaldean soldier, the wounded would still burn Jerusalem.
While the Chaldean forces were away (and the city not sealed), Jeremiah left Jerusalem to take care of some personal business in the territory of Benjamin. He was in the gate of Jerusalem that opens into Benjamin, when he was apprehended by an officer of the army named Yiriyah, who accused the prophet of trying to defect to the enemy. Of course, he denied the charges, but they wouldn't believe him. Jeremiah was arrested and thrown into prison, where he remained for a long time. (This prison was worse than the other - more "maximum security.") After a while, King Tzidkiyahu sent for him and privately asked if there was any prophecy from G-d that he should know about. There was: that Tzidkiyahu himself would fall into the hands of the Babylonians. Then Jeremiah asked what he had done to deserve imprisonment. "Where are your false prophets, who foretold good things?" Jeremiah asked the king. Finally, Jeremiah requested not to be returned to the prison, for he would surely die there. Tzidkiyahu had Jeremiah returned to the "minimum security" prison instead of the harsher one. He also granted him a daily loaf of bread, which continued until bread became unavailable. But Jeremiah did remain imprisoned.
(Yiriyah, the guard who arrested Jeremiah, was the grandson of Chananya, the false prophet in chapter 28. Falling into his hands was Jeremiah's punishment for dignifying Chananya's prophecy, even though he knew it was false. Presumably Yiriyah sought a pretext to arrest Jeremiah, to avenge his family's honor after the prophet showed up his grandfather.)