This question is addressed to the Assyrian invader, described as God's staff and rod. He was the means of inflicting deserved penalty on the world of that age, and especially on the Chosen People. He had no thought of this, but considered himself free to wreak his will without reference to that Higher Power whose agent he was. But the ruthless manner in which he carried out his work was destined to come under the divine judgment, Isaiah 10:12-15.
The capture of Jerusalem seemed as sure as the taking of a nest of eggs. The strongest barriers that the nations could oppose to his arms had fallen before the Assyrian king; and surely the Hebrew city should not escape. But God had yet to be reckoned with, Isaiah 10:16-19. The conception here is borrowed from a forest fire, which begins among the brushwood and presently consumes the loftiest and stoutest trees; so would the fire of destruction be kindled during the attack on the Holy City, which finally would involve the whole Assyrian empire. Let us not fear the wrath of man. God makes some portion of it to praise Him, and He restrains the remainder. [source]
Chapter Summary: Isaiah 10
1The woe of tyrants 5Assyria, the rod of hypocrites, for its pride shall be broken 20A remnant of Israel shall be saved 23Judah is comforted with promise of deliverance from Assyria