A.T. Robertson Commentary Matthew 28:18

"And Jesus came to them and spake unto them, saying, All authority hath been given unto me in heaven and on earth." — Matthew 28:18 (ASV)

All authority (πασα εξουσια). Jesus came close to them (προσελθων) and made this astounding claim. He spoke as one already in heaven with a world-wide outlook and with the resources of heaven at his command. His authority or power in his earthly life had been great (7:29; 11:27; 21:23f.). Now it is boundless and includes earth and heaven.

Hath been given (εδοθη) is a timeless aorist (Robertson, Grammar, pp. 836f.). It is the sublimist of all spectacles to see the Risen Christ without money or army or state charging this band of five hundred men and women with world conquest and bringing them to believe it possible and to undertake it with serious passion and power. Pentecost is still to come, but dynamic faith rules on this mountain in Galilee.