Obadiah is unique in the sense that he one of the only minor prophets to address a nation other than Israel or Judah. Most likely being a contemporary of Elijah and Elisha, He would call out Edom for their sins against God’s people.
As you can see, these people had a long history of rebellion against God’s people dating all the way back to the tension between Jacob and Esau.
At the time of this prophecy, Edom was safe and secure on their mountain while Israel had just been scattered into exile. When the Babylonians came, Edom not only didn’t help their relatives, they handed them over to be slaughtered. Edom even murdered some of the refugees and proceeded to plunder Jerusalem. Obadiah would bring a message of judgment to their continual disobedience.
“Since we know not how soon we may be called upon to suffer, we should feel compassion for rather than exultation in the sufferings of others. Malice harbored in any form contains the seed of future suffering. The great day of God is at hand, Oba 1:15, which shall bring retribution to all who have set themselves against the kingdom of God.”
F.B Meyer