Haftarah for Ki Seitzei
Isaiah compares Jerusalem to a barren woman, but he tells her to rejoice because the barren one has more children than the fertile one (referring to other nations that were not overrun). Jerusalem is told to make room for all her children, who are coming. They will spread out east and west, taking back other cities that had been abandoned or occupied by enemy forces. No longer will Jerusalem be ashamed, as she was in exile; her "widowhood" is over.
G-d is the Master of the world. He redeemed Israel and he will be recognized as G-d by the whole world. Israel is not really like a widow, because their "husband" (G-d) still lives. They were merely "separated," but now they are reconciled. G-d was angry with the Jewish people for but a short time; now He gathers them with great mercy and everlasting kindness.
This is like the flood in the time of Noah, during which time G-d swore never again to flood the Earth. Now He swears never to punish the Jews like this again. Mighty mountains will eventually be eroded away, but G-d's kindness and His covenant of peace will be with us forever.
Excerpted from The OU's Nach Yomi