The picture depicted of the king is one of someone who is incredibly unsure of not only what to do, but who are his advisers to whom he ought to listen? The chapter begins with a listing of some of the prophets of the king who were outraged by what Jeremiah was saying, basically which was to accept a terms of surrender to the Babylonians and you will be spared. If you do not, then this city and everyone in it will be burned. They complained because they said that this message was bad morale for the soldiers who were defending the city. Yes, that would be correct. If one of the prophets of the king says that it is no use fighting, and in fact fighting will only make matters worse, then if you are a soldier defending the city it just might put that thought in your head and it would inevitably lower morale.
So, as a result of Jeremiah’s preaching this controversial and toxic message we see the request by the other interested parties, or really the demand, is that the king put Jeremiah to death. The king says exactly as Pilate said to the mob who wanted to crucify Jesus, he is in your midst, he is yours to do as you please. I will not stop you. So they take him and put him in a dryish cistern waiting for him to die a very slow and painful death without food and water. Along came an Ethiopian eunuch (see Acts 8:26-40) who lobbied on Jeremiah’s behalf with the king in order to save him. The king, who previously had given the green light for the death of Jeremiah, now gives the green light in order for him to be saved.
Immediately after he is pulled up from the pit, vs.14ff, the king sends for him and makes a secret pinky swear promise type pact that Jeremiah ought to give him advice on what he ought to do and he promised his life would be safe if he did tell him. But he told Jeremiah not to tell a soul about their pinky promise deal that they had going on. Jeremiah tells him to surrender. It is interesting that the chapter ends with Jeremiah in the court of the king until Jerusalem surrenders, setting the stage to see whether the vision which the Lord had given Jeremiah would come true or not.
Without a doubt the king is depicted here as incredibly weak and someone who had no idea how to use his power for the good of the people. Every decision he made he looked over his shoulder to ensure that he would not be harmed by it.