What does Obadiah 1:7 mean?

Edom was located along major trade routes. The territory was rich in minerals, and the mountains were easy to defend. As a result, Edom had excellent trade relations with surrounding nations. Edom took pride in their strength, wealth, and popularity. They also considered themselves wise; after all, look how well they were doing! Obadiah's prophecy is part of a common thread in God's judgment. Often, people are repaid with the same kind of evil they subject others to. And, they frequently see their pride turned into humiliation.

According to history, shortly after this prophecy was written, Edom was defeated. The Nabateans, from Arabia, fooled the Edomites with a peaceful meeting. Once inside the borders, and with the Edomites lulled into carelessness, the Nabateans attacked and destroyed Edom. Given all of their pride, arrogance, and self-confidence, this was an embarrassing defeat. Obadiah's words directly mock the Edomites' arrogant claim to wisdom. Not only had they been beaten, but they had been deceived by an ally: "those who eat [their] bread."

This, again, hints at Edom's crimes against Israel. Since the two nations were descendants of brothers Esau and Jacob, they should have been friendly. Instead of an ally, Edom was a constant provoker against Israel. In the end, it was those Edom expected to be allies who defeated them.