Remember Edom and Daughter Babylon
The psalm turns from grief to an unsparing plea that Edom and Babylon receive the violence they inflicted. Verse 9 is an imprecatory cry from traumatized exiles, not a divine command to believers to kill enemy children. Revelation 18:6 plausibly reuses Psalm 137:8’s repay-Babylon logic in its judgment of symbolic Babylon, while the New Testament still forbids personal vengeance.