Shared ground
Isaiah 12:5–6 presents praise as both worship and public announcement. The text explicitly calls God’s people to sing to Yahweh because of what he has done (“excellent things”), and it explicitly says that this news is to be made known “in all the earth.” Praise is not portrayed as private or limited to one place.
The passage also holds together two locations at once: the message goes outward widely, yet the song’s center is Zion. Zion is addressed directly and urged to cry out and shout, because the “Holy One of Israel” is described as “great” and “in the midst of you.” The explicit claim is God’s greatness and nearness among his people.
Where interpretation differs
Some readers take “excellent things” as referring mainly to a particular rescue event (such as a deliverance from a military threat). Others read it more broadly as a summary of God’s mighty acts in general, without tying it to one episode.
A second difference concerns how to hear “in all the earth.” Some understand it as a strong way of saying “everywhere,” implying a worldwide horizon for the fame of Yahweh. Others take it as expansive language for broad international publicity (far beyond Judah), without requiring a statement about the whole globe.
Why the disagreement exists
The poem does not specify which “excellent things” are in view, and it gives no named event in these two verses. Also, the phrase “all the earth” can function either as universal language or as a conventional way to say “widely,” depending on context.
What this passage clearly contributes
These verses tie together three clear themes: (1) Yahweh’s deeds are the reason for praise (explicit), (2) praise is meant to spread as known “news” beyond the community (explicit), and (3) Zion’s loud joy is grounded in the Holy One’s greatness and presence “in the midst” of his people (explicit). The passage contributes a vision of worship that is audible and outward-facing while still anchored in God’s nearness to Zion. It also reinforces Isaiah’s recurring focus on the “Holy One of Israel” as central to how God is named and celebrated (inference from the title’s prominence in Isaiah).