Shared ground
This closing section of Psalm 107 portrays God as actively reshaping both the physical environment and human society. The text presents reversals: rivers become desert, deserts become springs; settled communities prosper, then shrink; leaders are brought down, and the needy are lifted up. These are not random swings of fate. The poem treats them as meaningful acts of God.
The passage also links moral life with land outcomes at least once: “fruitful land” becomes “salt waste” because of the wickedness of those living there (v.34). The ending frames the whole set of scenes as material for “the wise” to observe and think about, especially to recognize Yahweh’s many acts of loyal love (v.43). This “loyal love” is the psalm’s key lens for interpreting both relief and reversal.
Where interpretation differs
How direct the morality-to-land link is. Some take v.34 as a general rule: widespread wrongdoing reliably brings ecological collapse, while righteousness brings fertility. Others read it as one illustrative case within a broader theme: God can judge wickedness through land ruin, but not every drought or disaster can be mapped one-to-one onto specific sins.
How to read the sequence of reversals. Some read vv.33–41 as a repeating cycle (prosperity → decline → restoration) that communities commonly experience. Others read it more like a set of examples placed side by side to show God’s freedom to reverse conditions in either direction, without claiming a fixed pattern.
Who the “princes” are in vv.39–40. Some understand them as Israel’s local officials who abuse power and are humbled. Others think the language is broad enough to include foreign or imperial elites, or simply “leaders” in general.
Why the disagreement exists
The poem is deliberately compressed and illustrative. It uses broad, vivid images (salt wasteland, trackless waste, multiplying like a flock) rather than naming a specific event, place, or ruler. Because it is wisdom-like reflection at the end of a thanksgiving psalm, it invites general conclusions, but it also leaves open how strictly to apply those conclusions to particular cases.
What this passage clearly contributes
Explicitly, it claims God can overturn environmental conditions (vv.33–35), establish and sustain a settled community (vv.36–38), permit or bring social decline through oppression and sorrow (v.39), humble powerful leaders (v.40), and rescue and increase needy households (v.41). It also claims that at least sometimes land ruin is tied to human wickedness (v.34). By ending with reflection on Yahweh’s “lovingkindnesses” (v.43), it teaches that these reversals—whether in land or leadership—should be interpreted through God’s steadfast care rather than treated as meaningless accidents (cf. Psalm 107:1).