Without Ludlow, I would not have gotten much out of these two chapters. He does a wonderful job of summarizing and explaining everything. As these two chapters are heavy in history and light in doctrine and application, I will rely mostly on Ludlow's words.
"In 701 BC, Sennacherib, King of Assyria, launched the third military campaign of his reign, directing his armies toward the Mediterranean. His first objective was to reestablish the taxing of his rebellious tributaries, but he also hoped to bring them completely within the Assyrian Empire and to invade and subdue Egypt." (p. 316)
Sennacherib conquered many important cities along his way to Egypt. "Assyrian records and carvings portrayed with pride their techniques of conquest: hands and heads cut off, rebels impaled upon stakes, soldiers flung off walls, generals skinned alive, and multitudes led away as captives. Such a fate threatened the Jews in Jerusalem." (p. 317-318)
King Hezekiah prepared well years before the attack. He built a special tunnel to bring water from the spring of Gihon to within the city walls. He built and fortified the city and prepared the people. Ludlow cites 2 Chr. 32:1-8, 30.
Hezekiah also sent a monetary tribute to Sennacherib in hopes of staving off the attack (see 2 Kings 18:13-16). "But Sennacherib wanted more; he demanded absolute submission, and he knew that Hezekiah was one of the leaders in the revolt against Assyrian authority. He wanted nothing less than the unconditional surrender of Jerusalem, and he wanted her king still alive, so that he could humiliate, torture, and finally slowly impale King Hezekiah upon a pointed stake, just as he had done to the rebel kings of the Philistines." (p. 319)
• Isaiah 36:3 … a delegation is sent to meet Sennacherib's personal representative The Rabshakeh.
• Isaiah 36:4-7 … The Rabshakeh insults Jerusalem and scoffs at her allegiance with Egypt and with the Lord.
• Isaiah 36:8-10 … The Rabshakeh bets with them that they don't even have 2000 men to ride horses.
• Isaiah 36:11 … the delegation requests that the Rabshakeh talks to them in Aramaic as is the custom. Also, they don't want the people on the wall to listen.
• Isaiah 36:12-20 … The Rabshakeh denies the request and says he wants everyone to hear what he has to say. He shouts to the citizens on the wall and tries to bribe them to surrender the city by offering them farms. He tries to drive a wedge between them and their king. He mocks them by asking them if any of the other countries Sennacherib has conquered had their god save them. He tells them that their God will be no different.
• Isaiah 36:21-22 … The people on the wall don't respond and the delegation retreats to the city and rip their clothes to shreds as a sign of desperation.
• Isaiah 37:1-5 … Hezekiah also tears his robes and dresses in sackcloth as a sign of humility and mourning. He sends a message and a delegation to Isaiah. He requests Isaiah's prayers.
• Isaiah 37:6-7 … Isaiah replies to Hezekiah that a report will reach Sennacherib that he is needed at home and he will return home. There he will be killed.
• Isaiah 37:8-13 … Sennacherib is indeed distracted by the approaching Egyptian army. He continues to press Jerusalem to surrender by threatening annihilation of the city. Jerusalem will suffer the same fate as the other cities he has conquered.
• Isaiah 37:14-20 … Hezekiah takes the letter from Sennacherib to the Temple and prays to God. He tells God that the other cities' gods did not save them because they were false and that He, God, is indeed a living god. He pleads with God to save Jerusalem.
• Isaiah 37:21-29 … Isaiah speaks for the Lord and has a message sent to Sennacherib for Hezekiah. The Lord chides Sennacherib for being prideful and mocking the Lord. The Lord knows all and decided Sennacherib's fate long ago. The Lord is displeased with Sennacherib.
• Isaiah 37:30-32 … the Lord provides proof that He is delivering Jerusalem from Assyria. He gives a prophesy.
• Isaiah 37:33-38 … He prophesies that Sennacherib's army will depart and will be decimated by losing 185,000 soldiers. He also predicts that his sons will kill him.
The rest of the story is not found in the bible. But from other historical sources we learn that field mice overran Sennacherib's army and ate their bowstrings. Consequently they fled before the Egyptians. Ludlow also suggest that the mice may have carried the plague and the plague caused the 185,000 soldiers to die. Thus the prophecy was fulfilled.
The single most important lesson learned from these two chapters is that "the Lord defended the Jews and defeated the Assyrians." (Ludlow, 327) As an extension to our personal lives, how often do we trust in the Lord to deliver us from our problems and/or enemies? I am reminded what Christ taught, "seek ye first the kingdom of God and his righteousness, and all things shall be added unto you." (3 Nephi 13:33) If we focus on the Lord first and foremost, then everything else will be taken care of.