God rises to act, and judgment has a rescue-purpose
Verse 9 explains when and why the silence fell: it happened “when God arose to judgment,” picturing delayed action becoming visible action. The stated purpose is “to save all the afflicted ones of the earth,” so the judgment is presented as a decisive intervention that protects those brought low. “Selah” marks a pause to weigh the claim.
Unit 3 (vv. 8–9 together): Heaven-to-earth movement and the logic of cause
Taken together, the lines move from a heavenly pronouncement, to an earthly reaction, to the motive and goal of the action. The logic is: God’s announced decision leads to universal stillness because God is now actively stepping in as judge, and that action results in deliverance for the afflicted.