The Hebrews, like a fire, will consume the Edomites like stubble. If anything remains, they will scatter it. What David and Amaziah had begun was accomplished by the Jews after their return, when many Israelites who came back from Persia joined them, and the Edomites were deprived of any form of domination and were forced to change their religion and to embrace the Jewish rituals.
Source: COMMENTARY ON OBADIAH