Malachi 1:4

And to the same purpose he adds, If Edom shall say, We have been diminished, but we shall return and build houses; but if they build, I will pull down, saith God. He confirms what I have stated, that the posterity of Edom had no hope of restoration, for however they might gather courage and diligently labor in rebuilding their cities, they were not yet to succeed, for God would pull down all their buildings. This difference then was like a living representation, by which the Jews might see the love of God towards Jacob, and his hatred towards Esau. For since both people were overthrown by the same enemy, how was it that liberty was given to the Jews and no permission was given to the Idumeans to return to their own country? There was, as it has been said, a greater ill-will to the Jews, and yet the Chaldeans dealt with them more kindly. It then follows, that all this was owing to the wonderful purpose of God, and that hence it also appeared, that the adoption, which seemed to have been abolished when the Jews were driven into exile, was not in vain.

Thus then saith Jehovah of hosts, They shall build, that is, though they may build, I will overthrow; and it shall be said to them, Border of ungodliness, and a people with whom Jehovah is angry for ever. By the border of ungodliness he means an accursed border; as though he had said, “It will openly appear that you are reprobate, so that the whole world can form a judgment by the event itself.” By adding, A people with whom Jehovah is angry or displeased, he again confirms what I have said of love and hatred. God might indeed have been equally angry with the Jews as with the Edomites, but when God became pacified towards the Jews, while he continued inexorable to the posterity of Esau, the difference between the two people was hence quite manifest.

Noticed also must be the words, עד-עולם, od-oulam, for ever: for God seemed for a time to have rejected the Jews, and the Prophets adopt the same word זעם, som, angry, when they deplore the condition of the people, who found in various ways that God was angry with them. But the wrath of God towards the Jews was only for a time, for he did not wholly forget his covenant; but he became angry with the Edomites for ever, because their father had been rejected: and we know that this difference between the elect and the reprobate is ever pointed out, that when God visits sins in common, he ever moderates his wrath towards his elect, and sets limits to his severity, according to what he says, “If his posterity keep not my covenant, but profane my law, I will chastise them with the rod of man; but my mercy will I not take away from him.” (Psalms 89:31, 2 Samuel 7:14.) But with regard to the reprobate, God’s vengeance ever pursues them, is ever suspended over their heads, and ever fixed as it were in their bones and marrow. For this reason it is that our Prophet says, that God would be angry with the posterity of Esau.