III. He foretels the desolation that was now coming upon them. 1. God designs their ruin because they hate to be reformed (v. 21): I will lay stumbling-blocks before this people, occasions of falling not into sin, but into trouble. Those whom God has marked for destruction he perplexes and embarrasses in their counsels, and obstructs and retards all the methods they take for their own safety. The parties of the enemy, which they met with wherever they went, were stumbling-blocks to them; in ever corner they stumbled upon them and were dashed to pieces by them: The fathers and the sons together shall fall upon them; neither the fathers with their wisdom, nor the sons with their strength and courage, shall escape them, or get over them. The sons that sinned with their fathers fall with them. Even the neighbour and his friend shall perish and not be able to help either themselves or one another. 2. He will make use of the Chaldeans as instruments of it; for whatever work God has to do he will find out proper instruments for the doing of it. This is a people fetched from the north, from the sides of the earth. Babylon itself lay a great way off northward; and some of the countries that were subject to the king of Babylon, out of which his army was levied, lay much further. These must be employed in this service, v. 22, 23. For, (1.) It is a people very numerous, a great nation, which will make their invasion the more formidable. (2.) It is a warlike people. They lay hold on bow and spear, and at this time know how to use them, for they are used to them. They ride upon horses, and therefore they march the more swiftly, and in battle press the harder. No nation had yet brought into the field a better cavalry that the Chaldeans. (3.) It is a barbarous people. They are cruel and have no mercy, being greedy of prey and flushed with victory. They take a pride in frightening all about them; their voice roars like the sea. And, (4.) They have a particular design upon Judah and Jerusalem, in hopes greatly to enrich themselves with the spoil of that famous country. They are set in array against thee, O daughter of Zion! The sins of God's professing people make them an easy prey to those that are God's enemies as well as theirs.