But although He had done so many signs before them, they did not believe in Him, 38 that the word of Isaiah the prophet might be fulfilled, which he spoke:
“Lord, who has believed our report?
And to whom has the arm of the Lord been revealed?”
39 Therefore they could not believe, because Isaiah said again:
40 “He has blinded their eyes and hardened their hearts,
Lest they should see with their eyes,
Lest they should understand with their hearts and turn,
So that I should heal them.”
41 These things Isaiah said when he saw His glory and spoke of Him.
42 Nevertheless even among the rulers many believed in Him, but because of the Pharisees they did not confess Him, lest they should be put out of the synagogue; 43 for they loved the praise of men more than the praise of God. — John 12:37-43.
Isaiah … might be fulfilled (v.38). — Jesus’ earthly public ministry was a fulfillment of Isaiah’s prophecy, which was largely one of judgment upon unbelieving Israel. Jesus pronounces the judgment, previously announced by Isaiah, that must precede the coming kingdom.
saw his glory (v.41). — Isaiah had received a vision of the glory of the enthroned God (Is. 6:1) and prophesied about the divine Suffering Servant (Is. 52:13–53:12).
many believed in him (v.42). — Isaiah’s announced judgment came true, yet even some leaders (e.g., Joseph and Nicodemus, 19:38–40) were believers despite the threat of expulsion by their unbelieving peers.