Shared ground
This paragraph continues a larger reply to Zion’s fear that she has been forgotten (49:14–16). The text paints a dramatic reversal: the city that was emptied and ruined becomes crowded again, and the powers that harmed it are pushed out (vv. 17, 19).
Several claims are explicit. “Children” hurry back to Zion (v. 17), they gather from dispersal and come toward her (v. 18), and Yahweh seals the promise with a life-oath (v. 18). The returning people are compared to ornaments and bridal clothing—public honor and joy rather than shame (v. 18). The rebuilt population is so large that the land feels “too cramped” (vv. 19–20), and Zion herself is shocked at the sudden abundance after remembering bereavement, exile, and wandering (v. 21).
Where interpretation differs (only where needed)
One main question is what “children” refers to. Some read it mostly as the return of earlier Judean exiles and their families to Jerusalem. Others think the language allows for more than one source of “children”: both returnees and additional people newly attached to Zion, since the numbers seem to exceed what Zion thought she had lost (vv. 20–21).
A second question is how literal the “too cramped” picture is. Some take it as straightforward language for real repopulation and rebuilding. Others read it primarily as poetic exaggeration meant to convey overflowing restoration, whether or not space literally runs out.
Why the disagreement exists
The passage uses family metaphor (“children,” “bereavement,” “conceived,” “brought up”) to describe national loss and renewal, and metaphors can point both to concrete events (people returning) and to a larger vision (unexpected growth beyond what was imaginable). Also, the text does not identify the “children” by a specific group name, so readers infer from the exile background and from the scale of the described return.
What this passage clearly contributes
It portrays restoration as both removal and return: those who ruined Zion leave, and those who belong to her arrive (vv. 17, 19). It presents Yahweh’s commitment in unusually strong terms (“As I live,” v. 18), and it frames the restored community as Zion’s honor rather than merely her survival (v. 18). Finally, Zion’s astonished inner question (v. 21) contributes a key emotional note: restoration is not described as predictable recovery, but as surprising abundance after real loss.