Matthew Poole and continuators on Jeremiah 38:6

6 Then took they Jeremiah, and cast him into the dungeon of Malchiah the son of Hammelech that was in the court of the prison : and they let down Jeremiah with cords . And in the dungeon there was no water but mire, so Jeremiah sank in the mire .

A place much of the same nature with that of which we read, chap. 37.16. but in another prison.

It should seem there was no passage into it by stairs, so as they were forced to let him down with cords.

And in the bottom was nothing but mire, into which the Prophet sank, in respect of which circumstances, it was a much worse place then the dungeon in the prison, in Jonathans house appeared to be, though Jeremiah feared that he should dye there. It is probable these Princes thrust him into this place, designing he should dye in this hole a miserable death, but God otherwise provided for him.

Marginal references: Or, of the King