John 12:40,41 - He saw His glory

12:40

John then quotes from Is 6:10, words from the glorious vision that Isaiah saw. Isaiah saw a vision of the Lord, he was then overcome with his own guilt, and this guilt was taken away by the angel. God then asks “whom shall we send” and Isaiah gladly volunteers, only to be told that God has blinded the eyes of the people and they will not see. If they could see and believe then they would be saved. Note that “heal” here is referring to “healing” from sin, not physical healing. The situation was the same with Jesus and the Jews. He is a perfectly capable saviour. If they had believed then they would have been saved. 

12:41

“Isaiah said these things because he saw His glory and spoke of Him” (ESV). NIV has “he saw Jesus”. The text actually says “him”, and this is normally taken as referring to Jesus. The point that John is making is that this unbelief of the Jews was to be expected, and was all part of the plan. Paul makes a similar point in Rom 9-11. John says that Isaiah saw “His glory”. The unbelief of the Jews was not a setback, it was not a problem, rather it was all part of the plan.