Matthew Poole and continuators on Jeremiah 38:5

5 Then Zedekiah the king said, Behold, he is in your hand , for the king is not he that can do any thing against you .

That is in your power, either by the Established Law against false Prophets, or else I yield up my power to you, I surrender him into your hands; but neither of these seemeth very probable, for here is no mention of the sitting of the Sanhedrim to judge him as a false Prophet, nor of any judicial proceedings of that Nature: And it should seem by Zedekiahs relieving of him soon after from the dungeon, into which they threw him, that he had not surrendred Ieremiah so into their hands, but he reserved to himself a superintendency upon them to correct their too severe dealings with him. The meaning seems rather to be, if you will do any such thing, I shall not oppose you, but I will not be the Author of it.

I see I am as it were no King, I can do nothing against you, you will do what you please. I incline to this sense from the consideration of the favour shewed him by Zedekiah, both before, and after this.