Chapter thirty-three continues Isaiah’s description of the Messianic Kingdom, when Jehovah himself is ruling from Jerusalem. The beginning is addressed to the “destroyer” and “deceiver” who had not yet been destroyed or deceived (Isaiah 33:1). In Isaiah’s day, Israel feared destruction coming from Assyria, so this may be the reference. Isaiah asked for God’s mercy on Israel, as the only one who could deliver them from their distress, warning their enemies that is exactly what God would do (Isaiah 33:2-4). Even though the streets were empty, Isaiah knew that God would exalt himself, proving himself to be faithful to his promises and people (Isaiah 33:5-10).
Everything that the nations did that they thought provided them with power was nothing but “straw” and “chaff” (Isaiah 33:11-12). In fact, God would burn them to ashes as they breathed fire on everyone else. When this happened in Assyria (and will again in the future), the nations will finally realize that they cannot stand before Jehovah (Isaiah 33:13-14). God will reward those who obey his law (Isaiah 33:15-24). Israel will no longer be defiant against him, instead celebrating the festivals with pure hearts. Although they were at that time caught in the current headed for destruction, God would restore them after their punishment and make them strong and secure again, under his personal leadership. In that day both physical and spiritual sickness will be eradicated.