Brachos 8a: The time when Hashem desires prayer is when the congregation prays.

Rashi: At a time of Tefilah when you are pleasing and acceptable in front of Me.

Radak: Hashem tells Yisrael, when you do My will, I answer you, when you scream due to affliction that comes upon you. So Targum Yonasan explains.

Malbim: This corresponds to Ge'ulah before its time, if they merit, which verse 7 discusses.

Rashi: When you need salvation.

Malbim: This corresponds to Ge'ulah in its time, if they do not merit it earlier.

Rashi: I will guard you. Radak - even though you are liable to Me, in every generation I guard you from eradication.

Malbim: During the Galus, Hashem will guard you in three ways. (a) "Li'Vris Am" - He will establish the Bris that He made with Yisrael. (b) "Lehakim Eretz" - to establish the Eretz ha'Kedoshah. (c) "Lehanchil Nachalos Shemamos" - refer to 49:8:6:1.

Rashi: To be a nation that has a Bris with me.

Radak: This will be in the future, in the days of Mashi'ach, when you need to be sustenance of the nation - "Yekimcha Hashem Lo l'Am Kadosh" (Devarim 28:9).

Rashi: Eretz Yisrael, which is chosen to Me of all lands.

Radak: To establish the ruins of Eretz Yisrael.

Malbim: To raise Tzadikim who lie in the earth.

Radak, Malbim: To bequeath to you inheritances that were desolate the entire time of Galus. Malbim - i.e. the Azaros and the Mikdash, which were Nachalas Hashem.