God Is All-Knowing.

He reveals the deep and secret things which are hidden from the eyes of all living. It was he that revealed to man what is true wisdom when none else could (Job 27:27,28) it is he that reveals things to come to his servants and prophets. He does himself perfectly discern and distinguish that which is most closely and most industriously concealed, for he will bring into judgment every secret thing the truth will be evident in the great day. He knows what is in the darkness, and what is done in the darkness, for that hides not from him, Psalm 139:11,12. The light dwells with him, and he dwells in the light (1 Timothy 6:16), and yet, as to us, he makes darkness his pavilion. Some understand it of the light of prophecy and divine revelation, which dwells with God and is derived from him for he is the Father of lights, of all lights they are all at home in him. Secondly, For that he had made this discovery to him. Here he has an eye to God as the God of his fathers for, though the Jews were now captives in Babylon, yet they were beloved for their father's sake. He praises God, who is the fountain of wisdom and might, for the wisdom and might he had given him, wisdom to know this great secret and might to bear the discovery. Note, What wisdom and might we have we must acknowledge to be God's gift. - Matthew Henry