Matthew 28:18 - Ellicott's Commentary On The Whole Bible

All power is given unto me. — Literally, all authority was given, the tense used being that in which men speak of something that occurred at a given point of time. We may possibly connect it with St. Paul’s use of the same tense in the Greek of Philippians 2:8. The exaltation came, the authority was given, as at the moment of the Resurrection, and as the crown of His obedience unto death.