Verse 15 widens the charge past Edom. Until now Obadiah has named one nation and one betrayal. Now the frame pulls back: 15"the day of the LORD is near upon all the nations." What happened to Edom is one visible case of a rule that covers every nation. 15"As you have done, it shall be done to you; your deeds shall return on your own head."
The rule fits the crime and goes no further. Edom drank in triumph on God's holy mountain, gloating over Jerusalem's fall, and another psalm remembers how the Edomites cheered on the city's destruction (Psalm 137:7). Now 16"as you have drunk on my holy mountain, so all the nations shall drink continually." The same cup turns back on those who filled it, and the nations who drink it vanish as though they had never been. The judgment that fell on Edom's celebration is the same judgment waiting for anyone who cheers at another's fall.
Against that reckoning, verse 17 names what survives. 17"But in Mount Zion there shall be those who escape, and it shall be holy, and the house of Jacob shall possess their own possessions." The day that ends the nations who raised a hand against God's people is the day that restores what those people lost. The old family quarrel is settled the way verse 18 describes it: the house of Jacob is a fire, the house of Joseph a flame, and the house of Esau stubble. Israel does not win this by its own strength. The verse ends 18"for the LORD has spoken."
Verses 19 and 20 read like a deed redrawn, with each region and exiled community returned to what was its own. The exiles of Israel will 20"possess the land of the Canaanites as far as Zarephath," and the exiles of Jerusalem in Sepharad will possess the cities of the Negeb. The restoration is as specific as the accusation against Edom had been. God knows the names and places of the people who lost them.
The book ends with one sentence that outweighs every boundary drawn before it. 21"Saviors shall go up to Mount Zion to rule Mount Esau, and the kingdom shall be the LORD's." Whatever human deliverers Obadiah has in view, they rule only because the kingdom underneath them belongs to someone else. The book opened with a vision from the Lord GOD, and it closes with the same claim stated as fact. Edom's rock, wealth, wisdom, and allies are gone, and the kingdom is the LORD's.
We have no ground to stand on if that justice falls where our own deeds have earned it. That is why the last word matters. The day of the LORD is near for every nation, and the kingdom that outlasts it belongs to the Lord, which is safe news for those who take refuge in him and no comfort to those who trust a rock.
Prayer
Sovereign LORD, the justice that reached Edom reaches every nation, our own included, and we would have no ground if it fell where our deeds have earned it. Thank you that in Zion there are those who escape, and that you have spoken it. Let the truth that the kingdom is yours settle deep enough in us to change how we hold every claim we make on this world. In Jesus' name, amen.