What does Isaiah 10:34 mean?
Isaiah has traced the attack route of an invading army from the north all the way to a spot overlooking the city of Jerusalem. He leaves the fighters there "shaking their fists" at the city of Jerusalem (Isaiah 10:28–32).Suddenly, he changes scenes and pictures the Lord chopping down the tallest and mightiest of trees (Isaiah 10:33). Now Isaiah adds that the Lord will cut down the trees with an axe. The Lord God will even cut down "Lebanon," likely referring to the massive cedar trees of Lebanon.
The inescapable conclusion to this metaphor is that no matter how daunting the enemy attacking Jerusalem, the Lord will cut them down. When the time is right, the Lord will bring the invading nation down to size. Assyria will not succeed in sacking Jerusalem. God will stop them cold and end their empire's reign of terror.