John 20:21

Peace be unto you: as my father hath sent me, even so send. you.

Now that they know that he is their Master, he again repeats his blessing, and then reminds them of their work upon earth. As he had come to the world because the Father sent him, and represented the Father, so they, the apostles, are now sent by him and will speak his will. They are the executors of the Testament of Jesus Christ, the New Testament, that comes into force after the Testator dies, (Hebrews 9:15-17), and are to be sent forth to proclaim its provisions. This is the first development of the Great Commission, more fully developed in Galilee. little later, and finally completed on Mt. Olivet, just before the Lord ascended. The Lord had trained the apostles for three years in order to fit them for this important work.