Isaiah 10:12

"Wherefore it shall come to pass, that, when the Lord has performed his whole work upon mount Zion, I will punish the fruit of the stout heart of the king of Assyria, and the glory of his high looks. For he hath said, By the strength of my hand I have done it, and by my wisdom; for I have understanding: and I have removed the bounds of the peoples, and have robbed their treasures, and like a valiant man I have brought down them that sit on thrones: and my hand hath found as a nest the riches of the peoples; and as one gathers eggs that are forsaken, have I gathered all the earth: and there was none that moved the wing, or that opened the mouth, or chirped."

The interesting change of persons in Isaiah 10:12, from the second (the Lord) to the first (I will) is not at all unusual in the Old Testament.

No, God had not accepted the wickedness of a kingdom like Assyria. The rod of divine punishment was already laid up against that evil nation; and the reason was stated here. This arrogant and boastful power had bragged that they knew all of the answers. They thought they had the ability to destroy any nation on earth as handily as one could rob a bird nest and with no more opposition than a helpless little bird would be able to provide against such a catastrophe. There was not even the flutter of a wing, or the chirping of a bird. The rapacious cruelty and blood-lust of Assyria reached a pinnacle of such behavior in ancient history.