1 Corinthians 2:11
For who has knowledge of the things of a man but the spirit of the man which is in him? in the same way, no one has knowledge of the things of God but the Spirit of God.
Proverbs 20:27
The Lord keeps watch over the spirit of man, searching all the deepest parts of the body.
Jeremiah 17:9
The heart is a twisted thing, not to be searched out by man: who is able to have knowledge of it?
Proverbs 14:10
No one has knowledge of a man's grief but himself; and a strange person has no part in his joy.
Proverbs 20:5
The purpose in the heart of a man is like deep water, but a man of good sense will get it out.
Romans 11:33-34
O how deep is the wealth of the wisdom and knowledge of God! no one is able to make discovery of his decisions, and his ways may not be searched out.
1 Corinthians 2:10
But God has given us the revelation of these things through his Spirit, for the Spirit makes search into all things, even the deep things of God.