Cross reference
1 Corinthians 2:11
11 For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
Proverbs 20:27
27 The spirit of man is the candle of the LORD, searching all the inward parts of the belly.
Jeremiah 17:9
9 The heart is deceitful above all things, and desperately wicked: who can know it?
Proverbs 14:10
10 The heart knoweth his own bitterness; and a stranger doth not intermeddle with his joy.
Romans 11:33-34
33 O the depth of the riches both of the wisdom and knowledge of God! how unsearchable are his judgments, and his ways past finding out!
34 For who hath known the mind of the Lord? or who hath been his counsellor?
1 Corinthians 2:10
10 But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God.
Proverbs 20:5
5 Counsel in the heart of man is like deep water; but a man of understanding will draw it out.