Abraham is dead, and the prophets. — They still “do not understand His speech,” and take His words in a merely physical sense. In that sense they were impossible, for they are contradicted by the fact that death came to the great Patriarch and the prophets, and if to them, then surely, much more to ordinary men. They regard it as conclusive that their assertion in John 8:48 is correct. No one, except a man under the influence of a demon, would make an assertion so opposed to the almost unbroken experience of mankind.
If a man keep my saying. — Better, If a man keep My word, as in last verse.
He shall never taste of death. — The expression is stronger than that which He had used, “shall never see death.” They use it to put in the strongest way their wonder at the impossible promise which He had uttered. It has occurred before in Matthew 16:28. (See Note there.) It occurs again in the New Testament only in Hebrews 2:9.