Why herein is a marvellous thing. — Several of the better MSS. read more emphatically, the marvellous thing. He again puts two contradictory positions — their assertion that they knew not by what authority Jesus did these things (whence He was), and the evident fact that He had opened his eyes. He cannot reconcile their statement with what he knows to be true, and he states his wonder in the strongest form.
That ye know not from whence he is — i.e., ye whose business it is to know, ye who claim for yourselves a special knowledge of all such questions, and whose duty it is to inquire into the authority of any one who asserts that he is a teacher or a prophet. (Comp. Note on John 1:24.)