In The Theology of the Book of Isaiah, John Goldingay makes the historical narrative chapters a part of a collage dealing with the days of King Hezekiah that includes chapters 27-39.
Goldingay does not at all deal with the narratives in Isaiah 36-39 in terms of historical criticism.
He analyzes their message as it relates to the oracles of Isaiah that occur both within the narrative and in the earlier chapters of Isaiah.
Isaiah advocates a radical trust in Yahweh that must have seemed crazy to statesmen and the royal court. Judah must not rely on geopolitical strategies. The king must trust in God alone. Hezekiah moves toward Isaiah’s position. But chapter 39 with the king’s reception of a delegation from Merodach-Baladan II of Babylon shows that he was still into geopolitical strategy.
The mocking of Yahweh by the emissary from Sennacherib of Assyria sets the stage for the crisis depicted in these chapters. He speaks in the hearing of everyone saying and, surprisingly,makes the theological interpretation that Hezekiah’s religious reforms displease Yahweh and that, in fact, Yahweh has sent the Assyrian army to punish Judah (Isaiah 36:7-10).
This causes the king to turn to prayer. He sends his people to Isaiah to solicit his prayers. But Isaiah issues a prophecy that God will act by causing Sennacherib to hear of trouble at home and return there, where God will have him assassinated(Isaiah 37:7).
Goldingay does not comment on the fact that Isaiah’s prophecy corresponds closely to what we know happened historically. The problem is with the further report of a massive and sudden disaster for the Assyrian army (Isaiah 37:36). This is murky, historically.
There are hints in the fifth century account of Thucydides of a disaster related to an infestation of mice. Margaret Barker has put out a stimulating, but speculative scenario in which the Assyrian army, camped in siege of Lachish, suffered a mice-carried bubonic plague. (See here.) Of course, neither the biblical authors nor Thucydides would have known that mice spread plague. There is also the even more speculative theory that Hezekiah or even Isaiah poisoned the Assyrian’s water supply.
I do think something happened to cause a mass death among the Assyrians. Something gave rise to the horrible memory that we think of as a description of hell at the very end of Isaiah.
“They will go out and observe the corpses of those who rebelled against me, for the maggots that eat them will not die, and the fire that consumes them will not die out. All people will find the sight abhorrent” (Isaiah 66:24 NET Bible).
Goldingay does not concern himself with any of this. He does not even compare Isaiah’s account to the parallel accounts in 2 Kings 18-20 and 2 Chronicles 32. He is content to talk about how Hezekiah was called to trust God both for national security and for healing from a sickness that befell him.
The final verse of chapter 39 seems ironic or even cynical. We learn that Hezekiah’s private understanding of all this was that there would be peace and stability for the rest of his life.
“Perhaps the suggestion is less cynical than it sounds, in that it signifies that Yahweh will continue to have mercy upon Judah, will not treat it as it deserves and will postpone judgment, but Hezekiah’s story does end in ambiguity.”
This seems to me to fit well with the memory of Hezekiah in Jeremiah’s time. Jeremiah, mentioning the prophet Micah rather than Isaiah, appealed to the reputation of Hezekiah as a king who had appealed to God for mercy and received it (Jeremiah 26:19).