“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 12:34 — Greek Interlinear
Church Fathers on John 12:34
The Jews when they understood that our Lord spoke of His own death, asked how that could be: The people answered Him, We have heard out of the law that Christ abides for ever: and how say you, The Son of man must be lifted up? Who is this Son of man? Though our Lord did not call Himself the Son of man here, they remembered that He often called Himself so; as He had just before: The hour is come, that the Son of man should be glorified. They remember this, and ask, If Christ…
Hence we see, that they understood many of the things that He spoke in parables. As He had talked about death a little time before, they saw now what was meant by His being lifted up.