Proverbs 20:27, "The spirit of man is the candle of the LORD, searching all the inward parts of the belly." ~ King James Bible
"149:5.2 “Simon, some persons are naturally more happy than others. Much, very much, depends upon the willingness of man to be led and directed by the Father’s spirit which lives within him. Have you not read in the Scriptures the words of the wise man, ‘The spirit of man is the candle of the Lord, searching all the inward parts’?..."
That was Jesus quoting Proverbs 20:27. :)