John 8:14

‘Jesus answered and said to them, “Even if I do bear witness of myself, my witness is true, for I know from where I came and where I am going”.'

Jesus reply is that in His case the general principle is not true. This is because ‘I know where I have come from and where I am going'. This made Him a special case. As the heavenly Son of Man (John 3:13), who had come from Heaven and would return to Heaven, He had authority to testify about Himself, and indeed it was necessary, for no other man on earth could do so. He alone knew His source and His destiny. As with men's conceptions of the Messiah, His source was mysterious and unknown (John 7:27).