Shared ground
These verses combine petition and expectation. The speaker looks back on God’s past help (“what you have done for us”) and asks for that work to be reinforced (v. 28). God is assumed to be the source of the community’s strength, not merely a supporter of it.
The temple in Jerusalem is presented as a public sign of God’s kingship, strong enough that “kings” respond with gifts (v. 29). In the poem’s world, tribute is the normal political-language way to describe acknowledging a superior ruler.
At the same time, the psalm does not picture all nations as neutral. It asks God to confront violent, war-driven forces (v. 30). The animal images (“wild animal,” “bulls,” “calves”) point to threatening powers and their supporters, and the goal is their humbling and the end of war-making.
Finally, the passage widens the horizon beyond Israel by naming major foreign regions (Egypt and Cush) whose leaders come and “stretch out” hands to God (v. 31). However the gesture is pictured, the direction is toward Israel’s God rather than away from him.
Where interpretation differs
Who is the “wild animal of the reeds”? The text does not identify it. Some take it as a concrete political power known for river-land “reeds” (often suggested: a Nile-associated power), while others read it more generally as a poetic emblem for any hostile empire-like force.
What exactly are “bulls” and “calves of the peoples”? Some readers hear rulers and their elites (bulls) with their followings (calves). Others see armies or militarized nations as a whole. The verse supports either, because the images are collective and political but not precise.
What does it mean to “bring bars of silver”? It can be read as tribute brought by humbled opponents, or as wealth stripped from them after defeat, or as a symbolic way of saying “they will submit materially.” The line itself only states that, after humbling, silver is brought; it does not narrate how.
Why the disagreement exists
The poem uses compressed metaphors (animals, reeds, bulls) that work well for public worship but leave historical identification open. Also, the passage shifts quickly between prayer (“strengthen… rebuke… scatter…”) and confident future-sounding statements (“kings shall bring… princes shall come…”), making it less clear how much is immediate request versus anticipated outcome.
What this passage clearly contributes
Explicitly, the passage claims God has already acted for the community and is asked to continue that strengthening (v. 28). It links God’s recognized presence at Jerusalem’s temple with international tribute (v. 29). It asks God to confront and scatter war-loving nations, using vivid political-animal imagery (v. 30). It concludes with a picture of foreign leaders from named regions coming toward God with an embodied gesture of acknowledgment (v. 31). Theologically inferred (but consistent with these claims) is a vision of God’s rule extending beyond Israel, drawing both submission and worship while opposing militarized aggression.