Charles Spurgeon Commentary John 12:31-34

"Now is the judgment of this world: now shall the prince of this world be cast out. And I, if I be lifted up from the earth, will draw all men unto myself. But this he said, signifying by what manner of death he should die. The multitude therefore answered him, We have heard out of the law that the Christ abideth for ever: and how sayest thou, The Son of man must be lifted up? who is this Son of man?" — John 12:31-34 (ASV)

Now is the judgment of this world: now shall the prince of this world be cast out. And I, if I be lifted up from the earth, will draw all men unto me. This he said, signifying what death he should die. The people answered him, We have heard out of the law that Christ abideth for ever: and how sayest thou, The Son of man must be lifted up? who is this Son of man? (John 12:31–34)

As if it could not be true that Christ, in his divine nature, abides for ever, and yet, as Man, could be lifted up to die. It was a sneering question, "Who is this Son of man?" Our Lord did not answer it, thus teaching us that some people are not worth answering. Instead of replying to their question, Jesus gave them a practical admonition.