Shared ground

This passage presents Yahweh as fully aware of human action and intention (v.18). On that basis, he announces a coming moment when all nations and languages are gathered and made to “see” his glory—his publicly displayed honor and power (v.18).

It also depicts movement outward and inward: Yahweh sets a sign among the gathered and sends survivors to far places that have not heard of him, and those sent declare his glory among the nations (v.19). Then people from the nations bring Israel’s “brothers” back to Jerusalem as an offering, portrayed as fitting and honorable (v.20). Finally, Yahweh says he will take some from “them” for priestly and Levite service (v.21).

Where interpretation differs (only where needed)

What “a sign among them” is (v.19). The text does not identify the sign. Some read it as a concrete historical marker Yahweh sets in that generation; others take it more broadly as a future, recognizable act of God that becomes a public signal to the world.

Who the “survivors/escapes” are and what they escaped (v.19). Some understand them as survivors of a judgment or catastrophe connected to the chapter’s wider context; others read them more generally as people preserved by God who become messengers.

Who “your brothers” are (v.20). Many understand this primarily as dispersed Israelites being gathered back. Others think “brothers” can include a wider restored community, but the passage’s comparison to Israelites bringing offerings and the destination “Jerusalem” keep Israel centrally in view.

Who “them” refers to in v.21. Some take “them” to mean the returning Israelites, meaning Yahweh renews priestly service from within Israel. Others read “them” as the nations mentioned in vv.18–20, implying a surprising inclusion of non-Israelites in sacred service.

Why the disagreement exists

Several key nouns and pronouns are not pinned down by the immediate wording (“sign,” “those who escape,” “brothers,” “them”). The passage also moves quickly between “nations,” “survivors,” and “brothers,” so readers differ on which group is in view at each point. In addition, the list of distant places can be read either as literal geography or as a way of saying “to the ends of the known world,” which affects how concrete or symbolic the scene feels.

What this passage clearly contributes

• Yahweh’s concern and knowledge extend beyond Israel to all nations and languages (v.18).
• The nations are not only judged or observed; they are drawn into a scene where Yahweh’s glory becomes publicly known (vv.18–19).
• Yahweh’s purpose includes sending messengers to peoples who have not heard or seen (v.19).
• The return to Jerusalem is pictured as an act of honor toward Yahweh—people are brought as an “offering,” with language drawn from temple practice (v.20). Isaiah 66:1 keeps the temple in view as the passage’s symbolic center.
• Verse 21 pushes beyond expectations by linking the nations-and-return scene to priestly/Levite service, whether that means renewed service within Israel or expanded participation from the gathered peoples.