7 All the men of thy confederacy have brought thee even to the border: the men that were at peace with thee have deceived thee, and prevailed against thee; they that eat thy bread have laid a wound under thee: there is none understanding in him.
(Verse 7) All the men of your covenant have sent you to the borders, they have mocked you, the men of your peace have prevailed against you, those who eat with you have set a trap under you: there is no wisdom in him. 70: They have sent you to the borders: all the men of your covenant have resisted you, the men of your peace have prevailed against you: they have set a trap under you: there is no wisdom in him. As we explained earlier, when Esau searched and discovered his hidden things, they are distinguished to the borders: so the meaning is that your hidden and secret things have been revealed to the borders. But it seems better to us that he be joined with those who came later. Therefore, when Nebuchadnezzar came (of whom it is said in Jeremiah against Edom: Behold, like a lion he will ascend from the pride of the Jordan to the strong beauty, because I will make him run suddenly to it (Jer. 49:19): And then: Behold, like an eagle he will ascend and fly, and will spread his wings over Bozrah, and the heart of the mighty men of Edom will be like the heart of a woman in labor on that day (ibid. 49:22)), all those who were previously allied with Edom and had been in the garrison of the most proud city, left him and joined the enemies against him, and set traps for him: and they prevailed against him, and then it was made known that there was no wisdom in Edom: while he hoped in those who were shown to be his adversaries. Otherwise: When the hidden things of Esau, and as it were magnificent sacraments, by which previously the people had been ensnared, have been brought forth into the midst, so that the ecclesiastical man is able to say: For we are not ignorant of his cunning (2 Cor. 2), they will leave the borders of Edom, and abandon him, and migrating as far as the borders of the Church, they will bring forth the most wicked doctrines. Then they will mock and resist their former teacher, saying that what they had learned is false: they will prevail against him, and the learned ones in the faith of the Church will refute the false doctrine. Those who once ate with heretics will pose questions about the Scriptures, They will lay snares for the Idumean and the worldly, and they will be carnal in all things before the fleshly teacher (for we read about heresies that are counted among the works of the flesh in Galatians 5), and then it will be shown that there is no understanding in Edom.
[AD 420] Jerome on Obadiah 1:7