God tells Zeke to prophesy against the prophets of Israel that prophesy (v. 2) as if he hasn't been doing so for the past 12 chapters. There's a speech about walls that aren't up to code and how god is going to knock it down like a zealous city bylaw officer. Then he gets really mad at the women prophets, saying Woe to the women that sew pillows to all armholes, and make kerchiefs upon the head of every stature to hunt souls! (v. 18). Pillows apparently means charms. So some women were making charm bracelets and god is so petty and micro-managing and explosively over-reactionary that he's going to destroy them in revenge. I think god's still angry that back in grade 2 nobody would show him how to make gimp bracelets.
Zeke is sitting around with his friends drinking tea in that way men in the Middle East do when suddenly god tells him to tell them that they're all sinners and unless they repent they'll all be destroyed. Then god confesses that sometimes, just for the hell of it, he'll send a false prophecy to a prophet just so he can punish him for it, because he's just an asshole like that sometimes. And it's not just prophets! Basically, anytime anything bad happens to you or yours, including your kids, it's god, and he's doing it because you sinned.
Ever the environmentalist, god starts talking about vine trees and their many uses: you can build a house, hang stuff from it or burn it. But if it's just sitting there, doing its tree thing, it's useless, just like the ashes left over if you make a fire with it. And now he's going to set Jerusalem on fire.