This story of the rage and blasphemy of Sennacherib, Hezekiah's prayer, and the deliverance of Jerusalem by the destruction of the Assyrian army, we had more at large in the book of Kings, 2 Kings 18 and 19. It is contracted here, yet large enough to show these three things: -
I. The impiety and malice of the church's enemies. Sennacherib has his hands full in besieging Lachish (Ch2 32:9), but hears that Hezekiah is fortifying Jerusalem and encouraging his people to stand it out; and therefore, before he come in person to besiege it, he sends messengers to make speeches, and he himself writes letters to frighten Hezekiah and his people into a surrender of the city. See, 1. His great malice against the king of Judah, in endeavouring to withdraw his subjects from their allegiance to him. He did not treat with Hezekiah as a man of honour would have done, nor propose fair terms to him, but used mean and base artifices, unbecoming a crowned head, to terrify the common people and persuade them to desert him. he represented Hezekiah as one who designed to deceive his subjects into their ruin and betray them to famine and thirst (Ch2 32:11), as one who had done them great wrong and exposed them already to the divine displeasure by taking away the high places and altars (Ch2 32:12), and who, against the common interest of his people, held out against a force that would certainly be their ruin, Ch2 32:15. 2. His great impiety against the God of Israel, the God of Jerusalem he is called (Ch2 32:19), because that was the place he had chosen to put his name there, and because that was the place which was now threatened by the enemy and which the divine Providence had under its special protection. This proud blasphemer compared the great Jehovah, the Maker of heaven and earth, with the dunghill gods of the nations, the work of men's hands, and thought him no more able to deliver his worshippers than they were to deliver theirs (Ch2 32:19), as if an infinite and eternal Spirit had no more wisdom and power than a stone or the stock of a tree. He boasted of his triumphs over the gods of the nations, that they could none of them protect their people (Ch2 32:13-15), and thence inferred not only, How shall your God deliver you? (Ch2 32:14), but, as if he were inferior to them all, How much less shall your God deliver you? as if he were less able to help than any of them. Thus did they rail, rail in writing (which, being more deliberate, is so much the worse), on the Lord God of Israel, as if he were a cipher and an empty name, like all the rest, Ch2 32:17. Sennacherib, in the instructions he gave, said more than enough; but, as if his blasphemies had been too little, his servants, who learned insolence from their master, spoke yet more than he bade them against the Lord God and his servant Hezekiah, Ch2 32:16. And God resents what is said against his servants, and will reckon for it, as well as what is said against himself. All this was intended to frighten the people from their hope in God, which David's enemies sought to take him off from (Psa 11:1; Psa 42:10), saying, There is no help for him in God, Psa 3:2; Psa 71:11. Thus they hoped to take the city by weakening the hands of those that should defend it. Satan, in his temptations, aims to destroy our faith in God's all-sufficiency, knowing that he shall gain his point if he can do that; as we keep our ground if our faith fail not, Luk 22:32.
II. The duty as well as the interest of the church's friends, and that is in the day of distress to pray and cry to Heaven. So Hezekiah did, and the prophet Isaiah, Ch2 32:20. It was a happy time when the king and the prophet joined thus in prayer. Is any troubled? Is any terrified? Let him pray. So we engage God for us; so we encourage ourselves in him. Praying to God is here called crying to Heaven, because we are, in prayer, to eye him as our Father in heaven, whence he beholds the children of men, and where he has prepared his throne.
III. The power and goodness of the church's God. He is able both to control his enemies, be they ever so high, and to relieve his friends, be they ever so low.
1. As the blasphemies of his enemies engage him against them (Deu 32:27), so the prayers of his people engage him for them. They did so here. (1.) The army of the Assyrians was cut off by the sword of an angel, which triumphed particularly in the slaughter of the mighty men of valour, and the leaders and captains, who defied the sword of any man. God delights to abase the proud and secure. The Targum says, The Word of the Lord (the eternal Word) sent Gabriel to do this execution, and that it was done with lightning, and in the passover night: that was the night in which the angel destroyed the first-born of Egypt. But that was not all. (2.) The king of the Assyrians, having received this disgrace, was cut off by the sword of his own sons. Those that came forth of his own bowels slew him, Ch2 32:21. Thus was he mortified first, and then murdered - shamed first, and then slain. Evil pursues sinners; and, when they escape one mischief, they run upon another unseen.
2. By this work of wonder, (1.) God was glorified, as the protector of his people. Thus he saved Jerusalem, not only from the hand of Sennacherib, but from the hand of all others, Ch2 32:22; for such a deliverance as this was an earnest of much mercy in store; and he guided them, that is, he guarded them, on every side. God defends his people by directing them, shows them what they should do, and so saves them from what is designed or done against them. For this many brought gifts unto the Lord, when they saw the great power of God in the defence of his people. Strangers were thereby induced to supplicate his favour and enemies to deprecate his wrath, and both brought gifts to his temple, in token of their care and desire. (2.) Hezekiah was magnified as the favourite and particular care of Heaven. Many brought presents to him (Ch2 32:22, Ch2 32:23), in token of the honour they had for him, and to make an interest in him. By the favour of God enemies are lost and friends gained.

After this did Sennacherib - Having received the silver and gold mentioned above, he withdrew his army, but shortly after he sent Rab-shakeh with a blasphemous message. This is the fact mentioned here.

Thus saith Sennacherib king of Assyria, whereon do ye trust,.... On what power in heaven or on earth?

that ye abide in the siege in Jerusalem? hold out against the siege of it, and do not deliver it up.

(See on 2Ki. 18:17-35; also 2Ki. 19:8-34).