That they may possess the remnant of Edom and all the nations/And so the people of Israel will conquer what is left of the land of Edom and all the nations. The result of restoring the kingdom is that Israel’s military and political power will be extended once more over its original territory. The Hebrew makes this clause a continuation of the sentence in verse 11, but it is often better to start a new sentence with something like And so …
Who they refers to is not clear in Hebrew. They could be the kings descended from David, but it is probably better to interpret them as the Israelites in general: the people of Israel (compare Moffatt: “the people” and The Translator’s Old Testament: “his people”).
The remnant of Edom means what is left of the land of Edom or “Edom’s remaining territory” (The Translator’s Old Testament) or “Edom down to the last fragment (or: little bit).”
All the nations probably goes with the remnant of, that is, “what is left of all the nations/countries.”
Who are called by my name (Hebrew: over whom my name is called)/that were once mine. Good News Translation has the correct meaning. (Compare New English Bible: “who were once named mine”). It is also possible to say “which once belonged to me.” However, in translation this should not sound like the people of Israel will be conquering countries which once belonged to God, thus taking away from God what belonged to him. Good News Translation unfortunately could give this impression. The meaning is that under King David these countries had once been conquered by Israel, and because the Israelites who ruled them were God’s people, these countries also belonged to the LORD. A translation could run something like: “And so, the/you people of Israel will (be able to) conquer again what is left of the country of Edom and of all the other countries you once ruled for me.”
Says the LORD who does this/says the LORD, who will cause this to happen. See 1.5. In this case the expression says the LORD should not be left out even if the speaker has been named at the beginning of verse 11. Says the LORD is strengthened by who does this, which contributed to the climax as the book nears the end. One way of capturing the effect in English would be to say “That is what the LORD says—and that is what he will do.”
Quoted with permission from de Waard, Jan & Smalley, William A. A Handbook on Amos. (UBS Helps for Translators). New York: UBS, 1979. For this and other handbooks for translators see here .