Verse 3
A specific “day” is anticipated when yahweh will gives rest from sorrow, trouble, and hard service—language that combines emotional distress with coerced labor.
Verse 4
In response to that relief, the people take up a taunt against the king of Babylon, expressing astonishment that the oppressor has ceased.
Verses 5–6
The taunt’s logic is grounded in a reversal of power: the “staff” and “scepter” of wicked rule are broken. The former ruler is summarized as striking peoples continually and dominating nations through anger and relentless pursuit.
Verse 7
The effect is widened to “the whole earth,” portrayed as resting in quiet; the sudden absence of coercion is imagined as producing public celebration and song.