When the Lord has finished all his work against Mount Zion and Jerusalem, he will say, "I will punish the king of Assyria for the willful pride of his heart and the haughty look in his eyes." (NIV)
Therefore when the Lord has completed all His work [of chastisement and purification to be executed] on Mount Zion and on Jerusalem, it shall be that He will inflict punishment on the fruit [the thoughts, words, and deeds] of the stout and arrogant heart of the king of Assyria and the haughtiness of his pride. (AMP)
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. (KJV)