Isaiah says Jerusalem and Judah stumble because their words and deeds are against the LORD, provoking his presence (Isaiah 3:8). The chapter also describes leaders harming the people and crushing the poor, which becomes part of the stated charge in God’s judgment scene (Isaiah 3:13-15).
In Isaiah 3:8–11 the prophet states the charge against Jerusalem and Judah and then contrasts outcomes for two groups. The city’s collapse is not described as random misfortune but as the result of speech and behavior set against Yahweh. These verses sit within a larger section where Isaiah describes Jerusalem and Judah coming apart socially and politically, with leaders failing and people suffering (earlier in chapter 3).
Isaiah explains Jerusalem’s ruin and Judah’s fall as more than political bad luck. The passage ties collapse to a moral cause: what people say (“tongue”) and do (“doings”) is “against Yahweh” (verse 8). Their defiance is portrayed as deliberate and public—so visible it “testifies” against them (verse 9).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Isaiah 3:8, then read the surrounding section so the answer stays connected to the passage's flow.
8For Jerusalem is ruined, and Judah is fallen; because their tongue and their doings are against Yahweh, to provoke the eyes of his glory.