The Prophet here sets forth the reason why God would deal so severely and dreadfully with the Idumeans. Had he simply prophesied of their destruction, it would have been an important matter; for the Jews might have thereby known that their ruin was not chance, but the scourge of God; they might have known that they themselves were with others chastised by God, and this would have been a useful instruction to them: but what brought them the chief consolation was to hear, that they were so dear to God that he would undertake the defense of their wrongs and avenge them, that he would have a regard for their safety. Hence, when they heard that God, because he loved them, would punish the Idumeans, it was doubtless an invaluable comfort to them in their calamities. To this subject the Prophet now comes.

For the unjust oppression of thy brother Jacob, etc. The word חמס chemes, violence, is to be taken passively; as though he said, “See, how thou hast acted towards thy brother Jacob.” And he calls him his brother, not for honor’s sake, but, on the contrary, for the purpose of showing forth more fully the cruelty of the Idumeans; for consanguinity had had no effect in preventing them from raging against their own brethren, and as it were against their own bowels. It was therefore a proof of barbarous inhumanity, that the Idumeans, forgetting their common nature, had been so inflamed with hatred against their own brethren: for, as it is well known, they had descended from the same common father, Abraham, and also from Isaac, and had the symbol of circumcision. The Idumeans indeed professed that they were the descendants of Abraham, and were God’s peculiar people. Since then God had made his covenant with their common father Isaac, and since they had equally retained circumcision, which was the seal of that covenant, how did it happen, that the Idumeans conducted themselves so cruelly towards their brethren? We hence see, that the name of brother in this clause — for the oppression of thy brother Jacob, is mentioned for the purpose of enhancing their crime.

As then, he says, thou hast been so violent against thy brother, cover thee shall reproach, and forever shalt thou be cut off. He intimates that the calamity would not be only for a time as in the case of Israel, but that the Lord would execute such a punishment as would prove that the Idumeans were aliens to him; for God in chastising his Church ever observes certain limits, as he never forgets his covenant. He proves indeed that the Idumeans were not his people, however much they might falsely boast that they were the children of Abraham, and make claim to the sign of circumcision; for they were professedly enemies, and had entirely departed from all godliness: it was then no wonder that their circumcision, which they had impiously profaned, was made no account of. But he afterwards more fully and largely unfolds the same thing.

In the day, he says, in which thou didst stand on the opposite side”. But the Idumeans might have made this objection, “Why dost thou accuse us for having violently oppressed our brother? for we were not the cause why they were destroyed: they had a quarrel with the Assyrians, we labored to protect our own interest in the midst of these disturbances; we sought peace with the Assyrians, and if necessity so compelled us, that ought not to be ascribed to us as a crime or blame.” In this way the Idumeans might have made a defense: but the Prophet dissipates all such pretenses by saying, In the day in which thou didst stand on the opposite side, in the day in which strangers took away his substance, and aliens entered his gates, and cast lots on Jerusalem — were not thou there? Even thou were as one of them. Now this is emphatically introduced — Even thou or, thou also; (Tu etiam) for the Prophet exhibits it here as a hateful omen: “It was no wonder that the Assyrians and Chaldeans shed the blood of thy brethren, for they were enemies, they were foreigners, they were a very distant people: but thou, who were of the same blood, thou, whom the bond of religion ought to have restrained, and further, even thou, who oughtest by the very claims of vicinity either to have helped thy brethren, or at least to have condoled with them — yea, thou were so cruel as to have been as one of his enemies: this surely can by no means be endured.”

We now perceive what the Prophet meant by saying, In the day in which thou didst stand on the opposite side: it is then as it were, an explanation of the former sentence, lest the Idumeans should make a false excuse by objecting that they had not been violent against their brethren. It was indeed the worst oppression, when they stood over against them; though they were not armed they yet took pleasure in a spectacle so mournful; besides they not only were idle spectators of the calamity of their brethren but were also as it were a part of their enemies. “Hast thou then not been as one of them?” I shall not proceed farther now.