Now about the middle of the feast Jesus went up into the temple and taught.  And the Jews marveled, saying, "How does this Man know letters, having never studied?" 

Jesus answered them and said, "My doctrine is not Mine, but His who sent Me...  He who speaks from himself seeks his own glory; but He who seeks the glory of the One who sent Him is true, and no unrighteousness is in Him..."

John 7:14-18   (NKJV)