God will let the Israelites back into the temple if they promise to behave themselves. Is this the space currently occupied by The Dome of the Rock? because if it is, at this rate they're never going to get back in. He threatens to do to them what he did to Shiloh, which is not entirely clear, but does involve smiting, in the form of Philistines, which is a nice excuse. And what is he planning for the Jerusalemites? Burning. Burning the ever-loving shit out of the place, including the trees. Then he admits that he's sick of burnt offerings and tells them to eat the meat themselves. Or they can just send it over here. I love me a good barbecue. He finishes the chapter with a final threat: he'll kill them all and leave them to the vultures, then he'll shut up all mirth.
In the future, people will go into the ossuaries and bring out all the bones, until they cover the earth. And then they'll kill themselves rather than face god's wrath. Then he's going to give away all their stuff, including their wives. Jeremiah must write the most cheery holiday greeting cards. Also, it seems that if your wife leaves you, that's a really, really, bad sin and you shouldn't take her back, but if god gives her away to another dude, that's totally fine. In bizarro world.
Then, in case anyone has survived, god will send snakes and cockatrices (snakes hatched from chicken eggs) to bite all of us.
Jeremiah's reaction to this is the feigned shock and sorrow of a venal gossip who tells you all the bad things people are saying about you behind your back. And this is where the famous Is there no balm in Gilead; is there no physician there? why then is not the health of the daughter of my people recovered? (v. 22) line comes in.
Jeremiah laments what deceitful liars his people have become and tells us to trust no one, because they might be a non-believer. Is he Fox Mulder? So of course the solution is to destroy Jerusalem and let the dragons take over, then kill the people with tainted food and water, then run them through with a sword. They'll be dying so thick and fast their bodies will just rot where they fall. This will apply to the circumcised as well as the uncircumcised.