John 12:37-41

Even though He had done so many signs (attesting miracles) right before them, yet they still did not believe and failed to trust Him— This was to fulfill what Isaiah the prophet said: “LORD, WHO HAS BELIEVED OUR MESSAGE? AND TO WHOM HAS THE ARM (the power) OF THE LORD BEEN SHOWN (unveiled, revealed)?” [Is 53:1] Therefore they could not believe, for Isaiah said again, “HE HAS BLINDED THEIR EYES AND HE HARDENED THEIR HEART, TO KEEP THEM FROM SEEING WITH THEIR EYES AND UNDERSTANDING WITH THEIR HEART AND BEING CONVERTED; OTHERWISE, I [their God] WOULD HEAL THEM.” Isaiah said these things because he saw His glory and spoke about Him. [Is 6:9, 10]