What will Hashem heal?
Radak: Yerushalayim, which was mentioned above.
Why does it say "Aruchah" and "u'Marpei"?
Radak: The matter is repeated in different words.
Malbim: Aruchah is a cure [via this blow] for the external breakage. Marpei is a cure for the internal illness.
Why does it say "v'Gileisi"?
Radak: The Ketz (deadline for redemption) was hidden until the day of redemption.
Malbim: I will teach them [how great will be their Shalom and Emes].
What is "Ateres Shalom"?
Rashi: It is a Brachah of Shalom (greeting).
Radak: [It is much Shalom.] Ateres is always an expression of multitude. Regarding Tefilah, it refers to much Tefilah - "va'Ye'etar Yitzchak" (Bereishis 25:21). "V'Hatartem Alai Divreichem" (Yechezkel 35:13) is many words.
