'Mysteries' in the Bible

“He reveals mysteries from the darknessAnd brings the deep darkness into light.

However, there is a God in heaven who reveals mysteries, and He has made known to King Nebuchadnezzar what will take place in the latter days. This was your dream and the visions in your mind while on your bed.

As for you, O king, while on your bed your thoughts turned to what would take place in the future; and He who reveals mysteries has made known to you what will take place.

The king answered Daniel and said, “Surely your God is a God of gods and a Lord of kings and a revealer of mysteries, since you have been able to reveal this mystery.”