Edom lived in the area east of the Jordan in the mountainous areas south of the Dead Sea—a dry, barren, rocky place. Here, in this end-time prophecy, Edomites are still living in this inhospitable place.
Verse 1 contains a parenthetical statement that informs us that God has sent a messenger among the nations, urging them to "rise up against her." This is how things really work: God is the prime mover of world affairs. He determines His purpose and starts affairs rolling toward its fulfillment by inspiring an idea. Then the political and diplomatic mechanisms of nations take over to bring it to fruition, guided and pushed all the while by God (see Isaiah 46:9-11; Isaiah 55:11).
In this case, a national leader decides to send an ambassador to other nations to form a military alliance against Edom. The complaint, as explained in subsequent verses, is that Edom must be brought down to size, perhaps because she is not a team player, wanting all the glory and plunder for herself. That God is the ultimate author of this message means that it will happen as advertised.
Obadiah 1:2 adds emphasis to verse 1. The "I" is God Himself; it is His purpose to bring about Edom's national deflation. He wants Edom to recognize this! He thinks that the Edomites need to be brought into account for their actions and severely punished. Those among the nations who are scheming against Edom are merely agents God will use to fulfill His decree.
Verse 3 strikes at the root of Edom's problem: "The pride of your heart." It was easy for the Edomites to believe themselves to be invincible due to the nearly uninhabitable territory they dwelled in. To the west, where Israel lay, the geography made their territory nearly impregnable. Otherwise, they could feel secure because their fortresses were carved out of the rock, so they could either hunker down for long periods or engage in guerilla warfare. An attacking army could in no way pry them out, and they knew it. They felt invulnerable, and this filled them with pride.
"Pride" in verse 3 is the Hebrew word zadon, from the root, ziyd. This root is translated "cooked" in Genesis 25:29, where Jacob cooked a stew that the famished Esau desired. "Cooked" would be better translated "boiled" or "seethed." When heat is applied to water, it boils, and from this process, the Hebrews gained their understanding of pride.
Obadiah, it seems, specifically used this word to draw the reader's attention back to this incident, perhaps suggesting that Esau's selling of the birthright was rooted in his pride. Esau became heated and angry, and it manifested itself as haughtiness, arrogance, pride—the major trait he passed on to his descendants. Just as stew boils up under heat, so Edom puffs herself up thinking that she is self-reliant and invincible. God, however, is out to prove her wrong.
The Edomite challenge at the end of Obadiah 1:3 bears some scrutiny: "Who will bring me down to the ground?" This is remarkably similar to the words of Lucifer in Isaiah 14:13-14 and to those of the great harlot in Revelation 18:7. This same pride will lead Edom into trouble. The Bible declares that, in all three of these examples, God will have the last word: He will humble them all. In Obadiah 1:4, He decrees, no matter how high and mighty Edom considers herself to be, "from there I will bring you down."