This was to fulfill the word of Isaiah the prophet: “Lord, who has believed our message and to whom has the arm of the Lord been revealed?”
References for John 12:38
For this reason they could not believe, because, as Isaiah says elsewhere:
“He has blinded their eyes and hardened their hearts, so they can neither see with their eyes, nor understand with their hearts, nor turn—and I would heal them.”
References for John 12:40
Isaiah said this because he saw Jesus’ glory and spoke about him.
References for John 12:41