Shared ground
These verses present Jerusalem’s collapse as a public humiliation. The city that once carried a reputation for beauty and joy is now treated like a spectacle: people passing by mock, and enemies celebrate (explicit in vv. 15–16).
The text also offers an interpretation of why this is happening: Yahweh is not portrayed as surprised or defeated, but as acting according to a prior intention and prior “word” (explicit in v. 17). The enemies’ gloating is real, but it sits inside a larger claim that the disaster fulfills something previously announced.
Where interpretation differs
What the earlier “word…commanded in days of old” refers to. Some read it mainly as the covenant warnings and judgments laid down long ago (for example, in Torah and the established prophetic tradition). Others read it more narrowly as earlier prophetic announcements closer to the fall of Jerusalem (such as warnings delivered in the final generations before 586 BC). Both options fit the general idea that the disaster is presented as foretold rather than random.
How absolute “has not pitied” is. Some take it as an unqualified statement about this event: in this judgment, God did not hold back. Others take it as event-specific rhetoric typical of lament language—still describing severe judgment, but not claiming God is never compassionate.
Why the disagreement exists
The passage is brief and does not quote the earlier “word,” so readers infer its reference from broader biblical memory. Likewise, the poem’s emotional style can use absolute-sounding language to portray the total experience of ruin, which raises the question of whether statements like “no pity” are meant as a universal claim or as a description of this particular moment.
What this passage clearly contributes
It contributes a stark picture of reversal: a renowned city becomes an object of scorn. It also connects social shame (outsiders’ mockery) and geopolitical defeat (enemies’ triumph) to a theological claim: Yahweh’s declared intention has come to completion (v. 17). The enemies’ “we have swallowed her up” is presented as their boast (vv. 16), while the poem’s own explanation emphasizes divine purpose and fulfillment of an earlier word (v. 17).