Albert Barnes Commentary Isaiah 10:12

"Wherefore it shall come to pass, that, when the Lord hath performed his whole work upon mount Zion and on Jerusalem, I will punish the fruit of the stout heart of the king of Assyria, and the glory of his high looks." — Isaiah 10:12 (ASV)

Wherefore ... - In this verse God, through the prophet, threatens punishment to the king of Assyria for his pride and wicked designs.

His whole work - His entire plan regarding the punishment of the Jews. He sent the king of Assyria for a specific purpose to execute his justice on the people of Jerusalem. He would execute that plan entirely by the hand of Sennacherib, and would then inflict deserved punishment on Sennacherib himself for his wicked purposes.

Upon mount Zion - Mount Zion was a part of Jerusalem (see the note on Isaiah 1:8), but it was the residence of the court, the dwelling place of David and his successors. Perhaps here, where it is mentioned as distinct from Jerusalem, it refers to the court, the princes, nobles, or the government. ‘I will execute my purposes against the government and the people of the city.’

I will punish - Hebrew, ‘I will visit;’ but here, evidently used to denote punishment; see the note on Isaiah 10:3.

The fruit of the stout heart - Hebrew, ‘The fruit of the greatness of the heart.’ The ‘greatness of the heart’ is a Hebraism for pride of heart, or great, arrogant designs and plans formed in the heart. Fruit is that which a tree or the earth produces, and then anything which is produced or brought forth in any way. Here it means that which a proud heart had produced or designed; that is, plans of pride and ambition, schemes of conquest and of blood.

The glory of his high looks - Hebrew, ‘The glory of the lifting up of his eyes’ - an expression indicative of pride and haughtiness. The word glory here evidently refers to the self-complacency, and the air of majesty and haughtiness, which a proud man assumes. In this verse we see:

1. That God will accomplish all the purposes for which he designs wicked people to be the instruments. Their schemes will be successful only insofar as they contribute to his plans, and no further.
2. When that is done, they are completely in his power and under his control. He can halt their progress when he pleases and subdue them to his will.
3. The fact that they have been used to further the plans of God and to execute his designs will not free them from deserved punishment. That was not their intention; and they will be dealt with according to their intentions, and not according to God’s design to overrule them. Their plans were wicked; and if God brings good out of them, it is contrary to their intention; and hence, they are not to be exempted from punishment because he brings good out of their plans, contrary to their designs.
4. Wicked people are in fact often punished in this way. Nothing is more common on earth; and all the woes of hell will be an illustration of this principle. Out of all evil God will bring good; and even from the punishment of the damned themselves, he will take the opportunity to illustrate his own perfections and, in that display of his just character, promote the happiness of holy beings.