Chapter 33 The Sixth Woe Against Those Who Despoil Others and Who Are Treacherous.
The sixth woe seems in context to be directed against Assyria for some treacherous act. We can compare and contrast how the previous list of woes ended with a ‘ho' (or ‘woe') towards Assyria (Isaiah 10:5), but now Assyria has gone beyond the pale and receives ‘woe' instead. The treacherous act may be seen as occurring in 2 Kings 18:13-18 when Sennacherib accepted peace terms and tribute from Hezekiah but then later advanced and besieged Jerusalem. Behind his change of heart may have been news of the gathering of the Egyptian army, possibly supplemented by auxiliaries from Judah. No doubt he persuaded himself that he was justified because of this, but Jerusalem and Isaiah saw it as treachery, for they had had no part in the rebellion since the surrender.
Here the chapter then proceeds with a prayer to Yahweh, followed by a declaration of the victory He achieved, which resulted in an at least temporary transformation in Jerusalem as we would anticipate (Isaiah 33:2-6). But it would not last for long as the previous chapter has made clear. This is followed by further mourning over the act of treachery, and Yahweh's promise to respond to it, resulting in a description, as so often in Isaiah, of the triumph of God and the time of final blessing.