4. He must show how fatal their wickedness would be to their kingdom as well as to themselves, to Jerusalem especially, the royal city, v. 6-9. (1.) It is confessed that Judah and Jerusalem had been valuable in God's eyes and considerable in their own: thou art Gilead unto me and the head of Lebanon. Their lot was cast in a place that was rich and pleasant as Gilead; Zion was a stronghold, as stately as Lebanon: this they trusted to as their security. But, (2.) This shall not protect them; the country that is now fruitful as Gilead shall be made a wilderness. The cities that are now strong as Lebanon shall be cities not inhabited; and, when the country is laid waste, the cities must be dispeopled. See how easily God's judgments can ruin a nation, and how certainly sin will do it. When this desolating work is to be done, [1.] There shall be those that shall do it effectually (v. 7): "I will prepare destroyers against thee; I will sanctify them" (so the word is); "I will appoint them to this service and use them in it." Note, When destruction is designed destroyers are prepared, and perhaps are in the preparing, and things are working towards the designed destruction, and are getting ready for it, long before. And who can contend with destroyers of God's preparing? They shall destroy cities as easily as men fell trees in a forest: They shall cut down thy choice cedars; and yet, when they are down, shall value them no more than thorns and briers; they shall cast them into the fire, for their choicest cedars have become rotten ones and good for nothing else. [2.] There shall be those who shall be ready to justify God in the doing of it (v. 8, 9); persons of many nations, when they pass by the ruins of this city in their travels, will ask, "Wherefore hath the Lord done thus unto this city? How came so strong a city to be overpowered? so rich a city to be impoverished? so populous a city to be depopulated? so holy a city to be profaned? and a city that had been so dear to God to be abandoned by him?" The reason is so obvious that it shall be ready in every man's mouth. Ask those that go by the way, Job xxi. 29. Ask the next man you meet, and he will tell you it was because they changed their gods, which other nations never used to do. They forsook the covenant of Jehovah their own God, revolted from their allegiance to him and from the duty which their covenant with him bound them to, and they worshipped other gods and served them, in contempt of him; and therefore he gave them up to this destruction. Note, God never casts any off until they first cast him off. "Go," says God to the prophet, "and preach this to the royal family."