Nebuchadnezzar forgot that his splendid accomplishments were not really his own, but that he was accountable to the God of heaven for the wisdom and skill that produced his brilliant military, architectural, and administrative triumphs.
God reminded the king of his responsibility for the prosperity he enjoyed, especially in view of his knowledge of the divine purpose for him. Through difficult experience Nebuchadnezzar learnt the supreme lesson of his life.
From supreme monarch, Nebuchadnezzar was reduced to the society of dumb beasts, to eat as they eat, and to lodge with them under the open sky. His brilliant intellect was reduced to the instinctive processes of their extremely limited minds.
Insanity descends upon the brilliant mind of the king, obliterating everything. Reason departs; the mental faculties fail. The light of intelligence fades from his eyes, and in its place there remains nought but the blank, glassy stare that marks the dumb brute, and with it an elemental desire for a few blades of grass to eat and a pile of straw on which to spend the night.
No longer does Nebuchadnezzar envision himself as the builder of Babylon and the ruler of a vast empire whose borders touch the ends of the earth. He is an ox!
What did Nebuchadnezzar learn about God through this experience? Dan. 4:32, 34-37.
The once proud monarch had become a humble child of God; the tyrannical, overbearing ruler, a wise and compassionate king. He who had defied and blasphemed the God of heaven, now acknowledged the power of the Most High, and earnestly sought to promote the fear of Jehovah and the happiness of his subjects.
“Under the rebuke of Him who is King of kings and Lord of lords, Nebuchadnezzar had learned at last the lesson which all rulers need to learn–that true greatness consists in true goodness.” Prophets and Kings, page 521.