The book of Daniel constantly refers to Aramaic words like "mystery" (רז; raz), "vision" (חזו; hezev), and "dream" (חלום; halom). Nebuchadnezzar summons diviners and magicians to reveal (גלה; galah) these things, but many of them are unsuccessful in their attempts. What they don’t see is that revelation is a divine prerogative. Only the Most High God can reveal true wisdom.
Daniel’s song of praise highlights the revelatory nature of wisdom: "Daniel spoke and said, 'Blessed be the name of God from everlasting to everlasting, for wisdom (חכמתא; hokhmata) and might are His.' And He changes the times and the seasons, He removes kings and He sets up kings, He gives wisdom to the wise, and knowledge to them that know understanding.' He reveals (גלא; gale') the deep and secret things; He knows what is in the darkness and the light dwells with Him." (Dan 2:20-22)
God revealed the mystery of Nebuchadnezzar’s dream to Daniel; the mystery of the divine kingdom. Nebuchadnezzar didn’t forget his dream and he asked his diviners and magicians to interpret it. If they could tell him his dream, he knew that they had true wisdom. But they fell short. It was only due to God’s revelation to Daniel that Nebuchadnezzar would understand the mysteries behind his dreams.
Here in Daniel 2 we see the contrast between the abilities of humanity and the power of God. No diviner, no magician, no Chaldean, could ever possess the knowledge of the divine… unless the Lord imparted it to them. Daniel received this wisdom not for his benefit, but for the king’s benefit in making the interpretation known and relieving his discomfort. Daniel 2:30 says, “But as for me, this secret is not revealed to me for any wisdom that I have more than any living, but to the intent that the interpretation may be made known to the king, and that you may know the thoughts of your heart.”
Thus, it is God who uncovers the mysteries, who uncovers the secret things for which the diviners and magicians couldn’t muster an explanation. This is because true wisdom is a mystery and true revelation is only in the realm of God.