So this is what the LORD says about the king of Assyria: ‘He will not enter this city or shoot an arrow into it. He will not come before it with a shield or build up a siege ramp against it.
We have here the gracious copious answer which God gave to Hezekiah's prayer. The message which he sent him by the same hand (Kg2 19:6, Kg2 19:7), one would think, was an answer sufficient to his prayer; but, that he might have strong consolation, he was encouraged by two immutable things, in which it was impossible for God to lie, Heb 6:18.
Commenting on 2 Kings 19:20-34
HEZEKIAH'S PRAYER. (2Ki. 19:14-34) Hezekiah received the letter . . . and went up into the house of the Lord--Hezekiah, after reading it, hastened into the temple, spread it in the childlike confidence of faith before the Lord, as containing taunts deeply affecting the divine honor, and implored deliverance from this proud defier of God and man.
Commenting on 2 Kings 19:14-34
He shall not, etc. - Here follow the fullest proofs that Jerusalem shall not be taken by the Assyrians. 1. He shall not come into this city; 2. He shall not be able to get so near as to shoot an arrow into it; 3. He shall not be able to bring an army before it, 4.