“Therefore they could not believe. For again Isaiah said, “He has blinded their eyes and hardened their heart, lest they see with their eyes, and understand with their heart, and turn, and I would heal them.” (John 12:39-40 ESV)
Most of the people in Jerusalem on that Palm Sunday had seen or heard of the signs and miracles that Jesus had performed. Some believed that He was the Messiah, others thought He was a prophet sent from God, but still many, the Pharisees among them, saw Him as a threat to be eliminated. This is why John cited Isaiah 6:9-10, which was part of the commission that the Lord had given the prophet following the vision of the Lord God Almighty in His full majestic glory.
What Isaiah had seen of the Lord stands in stark contrast to the sinfulness of his fellow Jews most of whom had fallen into idolatry. Isaiah’s message to them was one of the Lord’s coming judgment. He was not someone that they could manipulate or fool, but because they had refused to trust, serve, and Him, the prophet pronounced them to be blind and stubborn, hard of heart, and worthy of judgment. Yet there was still hope for the people who the Lord was sending into exile: He was not going to desert them.
John’s citation of Isaiah indicates that the Jews who rejected Jesus on Palm Sunday and again at His crucifixion and later, were rejecting God, just as their ancestors had. The Lord hardened their hearts because of their rebellious attitude. The same is true today of all those who reject Jesus. There will come a time when they will no longer be offered an opportunity to accept the gift of faith and eternal life which He offers. Then the Lord will give them what they want: an existence without Him. This thought should sadden us. It ought to provoke us to present the gospel to our friends, family and neighbors before their hearts are closed. Who knows that the words we say or actions we perform in the name of Jesus will lead them away from eternal punishment into His loving arms.,