17 That is why the Lord takes no pleasure in the young men and shows no mercy even to the widows and orphans. For they are all wicked hypocrites, and they all speak foolishness. But even then the Lord 's anger will not be satisfied. His fist is still poised to strike. 18 This wickedness is like a brushfire. It burns not only briers and thorns but also sets the forests ablaze. Its burning sends up clouds of smoke. 19 The land will be blackened by the fury of the Lord of Heaven's Armies. The people will be fuel for the fire, and no one will spare even his own brother. 20 They will attack their neighbor on the right but will still be hungry. They will devour their neighbor on the left but will not be satisfied. In the end they will even eat their own children.
Matthew Henry's Commentary on Isaiah 9:17-20
Commentary on Isaiah 9:8-21
(Read Isaiah 9:8-21)
Those are ripening apace for ruin, whose hearts are unhumbled under humbling providences. For that which God designs, in smiting us, is, to turn us to himself; and if this point be not gained by lesser judgments, greater may be expected. The leaders of the people misled them. We have reason to be afraid of those that speak well of us, when we do ill. Wickedness was universal, all were infected with it. They shall be in trouble, and see no way out; and when men's ways displease the Lord, he makes even their friends to be at war with them. God would take away those they thought to have help from. Their rulers were the head. Their false prophets were the tail and the rush, the most despicable. In these civil contests, men preyed on near relations who were as their own flesh. The people turn not to Him who smites them, therefore he continues to smite: for when God judges, he will overcome; and the proudest, stoutest sinner shall either bend or break.