Then the house of Jacob will be a blazing fire, and the house of Joseph a burning flame; but the house of Esau will be stubble—Jacob will set it ablaze and consume it. Therefore no survivor will remain from the house of Esau.” For the LORD has spoken.
Here again the Prophet meets a doubt, which might come into the mind of each of them; for the Idumeans were flourishing, and their condition was independent, when the Israelites as well as the Jews were led into exile, and Jerusalem with its temple was destroyed.
After the destruction of the church's enemies is threatened, which will be completely accomplished in the great day of recompence, and that judgment for which Christ came once, and will come again, into this world, here follow precious promises of the salvation of the church, with which this prophecy concludes, and those of Joel and Amos did, which, however they might be in part fulfilled...
Commenting on Obadiah 1:17-21
And the house of Jacob shall be a fire, and the house of Joseph a flame,.... The former may denote the two tribes of Judah and Benjamin, the latter the ten tribes, which after the separation in Rehoboam's time were called Ephraim, and sometimes Joseph; though they may here signify one and the same, since all the tribes will be united, and become one people...