The people could not fit a dying Messiah into what they had been taught. They had heard "out of the law that Christ abideth for ever," so how could He be lifted up? Barnes explains: "The doctrine of many of them certainly was that the Messiah would not die; that he would reign as a prince forever over the people." They understood "lifted up" as a violent death. Their second question asks who this Son of man could be. Barnes says that, "Either ignorantly or willfully, they supposed he referred to some one else than the Messiah," while Gill puts their thought as, "is there any other son of man besides the Messiah?"

Jesus did not argue the point. He answered with an urgent warning: "Yet a little while is the light with you. Walk while ye have the light, lest darkness come upon you" (John 12:35). He urged them, "While ye have light, believe in the light, that ye may be the children of light" (John 12:36). Then He "departed, and did hide himself from them." Barnes notes that Jesus did not reply directly to their question but pressed them to use the light they had.

By "the law" the people meant the Scriptures in general. Barnes and Gill both point to Psalm 110:4, "Thou art a priest for ever," and Barnes also to Daniel 2:44, where God sets up a kingdom that "shall stand for ever." The verb "lifted up" is hupsoo, which Thayer defines as "to lift up on high, to exalt." John uses it for Jesus' death in John 3:14, John 8:28, and John 12:32, and explains it as "signifying what death he should die" (John 12:33). Matthew Henry says the people "drew false notions from the Scriptures, because they overlooked the prophecies that spoke of Christ's sufferings and death."

The crowd's question is honest in one way: they were trying to square Jesus' words with Scripture. But they had read only half the story. The same Scriptures that promised a Christ who abides for ever also foretold His suffering. Right after this exchange John quotes Isaiah, "Lord, who hath believed our report?" (John 12:38), from the very chapter that describes the Servant who "is despised and rejected of men" (Isaiah 53:1, 3).

Jesus is the answer to both questions. He is the Son of man who is lifted up on the cross, and He is the Christ who abides for ever. His reply, "believe in the light," shows what He wanted most from them. Not a debate won, but faith while there was still time.