And therefore will the LORD wait, that he may be gracious unto you, and therefore will he be exalted, that he may have mercy upon you: for the LORD is a God of judgment: blessed are all they that wait for him.
And therefore will the Lord wait, that he may be gracious unto you - "therefore" He will wait, or delay in punishing, to give you time for escape from the coming evils by repentance (Isaiah 30:13-14; Isaiah 30:17) (Maurer). For "And therefore" (Hebrew, wªlaakeen (H3651)), translate, Yet therefore (namely, because of the distress spoken of in the previous verses; that distress will be overruled by the grace of God to lead the Jews to repentance, and so Yahweh will pity them) (Gesenius). So "therefore" is used Isaiah 51:21; Isaiah 20:1-6. Though they hastened to forsake Him for Egypt, He will not repay them in kind, but will "wait," instead of hastening to forsake them. Through compassion, at the miseries which are before you, if still impenitent (Isaiah 30:19), He waits for a change in you, so that it may be consistent with His justice not to punish, but to "be gracious unto you." Blessed, (therefore), are all they that wait for him (even as He waits for them) - instead of impatiently having recourse to Egypt for help.
And therefore will he be exalted - through His interposition in your behalf.
That he may have mercy upon you - and deliver you from the enemy-the Assyrian host of Sennacherib in this case, though ultimately the last antichristian foes of Israel are contemplated. Men will have more elevated views of God's mercy, or else 'He will be exalted (i:e., He will ascend his tribunal, which he had seemed to have forsaken), that He may have mercy upon you, and save you from the enemy' (Calvin).
For the Lord (is) a God of judgment - justice; faithfulness to His covenant with His people, and executing judgment in their behalf upon their foes.
Blessed (are) all they that wait for him - namely, for His times of having mercy (cf. Isaiah 30:15).