Here he indicates the prisoners of both the kingdoms of Samaria and Jerusalem, and also those who had gone to very far regions. Therefore he recalls the transmigration to Spain, because this is the name of a province, which is extremely distant from Judea, in order to show that this is the great gathering, which God had promised to bring together again from the four corners of the world. Those who have been saved shall go up to Mount Zion to rule Mount Esau, in order to defeat and destroy the nation of the Edomites. And the kingdom shall be the Lord's. All the nations will be subjugated and subjected to the people of God, that is, to the people that God shall make.
Source: COMMENTARY ON OBADIAH