A.T. Robertson Commentary John 12:40

"He hath blinded their eyes, and he hardened their heart; Lest they should see with their eyes, and perceive with their heart, And should turn, And I should heal them." — John 12:40 (ASV)

He hath blinded (τετυφλωκεν). Perfect active indicative of τυφλοω, old causative verb to make blind (from τυφλος, blind), in N.T. only here, 2 Corinthians 4:4; 1 John 2:11.

He hardened (επωρωσεν). First aorist active indicative of πωροω, a late causative verb (from πωρος, hard skin), seen already in Mr 6:52, etc. This quotation is from Isa 6:10 and differs from the LXX.

Lest they should see (ινα μη ιδωσιν). Negative purpose clause with ινα μη instead of μηποτε (never used by John) of the LXX. Matthew (Matthew 13:15) has μηποτε and quotes Jesus as using the passage as do Mark and Luke (Luke 8:10). Paul quotes it again (Acts 28:26) to the Jews in Rome. In each instance the words of Isaiah are interpreted as forecasting the doom of the Jews for rejecting the Messiah. Matthew (Matthew 13:15) has συνωσιν where John has νοησωσιν (perceive), and both change from the subjunctive to the future (κα ιασομα), "And I should heal them." John has here στραφωσιν (second aorist passive subjunctive of στρεφω) while Matthew reads επιστρεψωσιν (first aorist active of επιστρεφω).