Who art thou? - As Jesus did not expressly say in the previous verse that he was the Messiah, they professed still not to understand him. In great contempt, therefore, they asked him who he was. As if they had said, “Who art thou that undertakest to threaten us in this manner!” When we remember that they regarded him as a mere pretender from Galilee; that he was poor and without friends; and that he was persecuted by those in authority, we cannot but admire the patience with which all this was borne, and the coolness with which he answered them.
Even the same ... - What he had professed to them was that he was the light of the world; that he was the bread that came down from heaven; that he was sent by his Father, etc. From all this they might easily gather that he claimed to be the Messiah. He assumed no new character; he made no change in his professions; he is the same yesterday, today, and forever; and as he had once professed to be the light of the world, so, in the face of contempt, persecution, and death, he adhered to the profession.
The beginning - From his first discourse with them, or uniformly.