Bede the Venerable — as excerpted in the Catena Aurea on Mark 6:6-13

“(in Marc. 2, 24) Now our kind and merciful Lord and Master did not grudge His servants and their disciples His own virtues, and as He Him self had healed every sickness and every infirmity, so also He gave the same power to His disciples. Wherefore it goes on: And he called unto him the twelve, and began to send them forth by two and two; and gave them power over unclean spirits. Great is the difference between giving and receiving. Whatsoever He does, is done in His own power, as Lord; if they do any thing, they confess their own weakness and the power of the Lord, saying in the name of Jesus, Arise, and walk.”