Luke 24:45 - Ellicott's Commentary On The Whole Bible

Then opened he their understanding. — Assuming, as we must assume, that this was the same meeting of the Lord with His disciples as that reported in John 20:22, we have here that which corresponds with the gift of the Holy Spirit He then imparted to them. They were conscious of a new spiritual power of insight and knowledge which they had not possessed before. St. Luke’s report, as derived probably at second or third hand, through Joanna or others, is naturally more vague than that which comes from the eye-witness.