The words "a waste" and "desolate" mean basically the same thing and emphasize that the enemy has destroyed Zion and left it empty. AT: "Though you were completely desolate" (See: [[rc://en/ta/man/translate/figs-doublet]])
# The children born during the time of your bereavement
Yahweh speaks of the time when the people of Jerusalem were in exile as if the city was bereaved of her children. Those who were born while the people were in exile are spoken of as the city's children. AT: "Those who will inhabit you, who were born while the people were in exile" (See: [[rc://en/ta/man/translate/figs-metaphor]])
# The place is too cramped for us
This means that there will be so many people that the city will be too small for them all to live in it.