1. The sin of the Edomites, v. 12. They not only triumphed in the ruin of Judah and Jerusalem, as the Moabites and Ammonites had done, but they took advantage from the present distressed state to which the Jews were reduced to do them some real mischiefs, probably made inroads upon their frontiers and plundered their country: Edom has dealt against the house of Judah by taking vengeance. The Edomites had of old been tributaries to the Jews, according to the sentence that the elder should serve the younger. In Jehoram's time they revolted. Amaziah severely chastised them (2 Kings xiv. 7), and for this they took vengeance. Now they would pay off all the old scores, and not only incensed the Babylonians against Jerusalem, crying, Rase it, rase it (Ps. cxxxvii. 7), but cut off those that escaped, as we find in the prophecy of Obadiah, which is wholly directed against Edom, v. 11, 12, &c. It is called here revenging a revenge, which intimates that they were not only eager upon it, but very cruel in it, and recompensed to the Jews more than double. "Herein he has greatly offended." Note, It is a great offence to God for us to revenge ourselves upon our brother; for God has said, Vengeance is mine. We are forbidden to revenge or to bear a grudge. Suppose Judah had been hard upon Edom formerly, it was a base thing for the Edomites now, in revenge for it, to smite them secretly. But the Jews had a divine warrant to reign over the Edomites, for that therefore they ought not to have made reprisals; and it was the more disingenuous for them to retain the old enmity when God had particularly commanded his people to forget it. Deut. xxiii. 7, Thou shalt not abhor an Edomite.