Proverbs 25:2 NIV

Deuteronomy 29:29 niv
The secret things belong to the Lord our God, but the things revealed belong to us and to our children forever, that we may follow all the words of this law.

Romans 11:33-34 niv
Oh, the depth of the riches of the wisdom and knowledge of God! How unsearchable his judgments, and his paths beyond tracing out! “Who has known the mind of the Lord? Or who has been his counselor?”