From: Mark 6:7-13
The Mission of the Twelve
 And he (Jesus) called to him the Twelve, and began to send them out two by two, and gave them authority over the unclean spirits.  He charged them to take nothing for their journey except a staff; no bread, no bag, no money in their belts;  but to wear sandals and not put on two tunics.  And he said to them, "Where you enter a house, stay there until you leave the place.  And if any place will not receive you and they refuse to hear you, when you leave, shake off the dust that is on your feet for a testimony against them."  So they went out and preached that men should repent.  And they cast out many demons, and anointed with oil many that were sick and healed them.
7. Cf. note on Mk 1:27; 3:14-19.
[The note on Mk 1:17 states:
27. The same authority that Jesus showed in His teaching (1:22) is now to be seen in His actions. His will is His command: He has no need of long prayers or incantations. Jesus' words and actions already have a divine power which provokes wonder and fear in those who hear and see Him.
Jesus continues to impress people in this way (Mark 2:12; 5:20-42; 7:37; 15:39; Luke 19:48; John 7:46). Jesus of Nazareth is the long-awaited Savior. He knows this Himself and He lets it be known by His actions and by His words; according to the gospel accounts (Mark 1:38-39; 2:10-11; 4:39) there is complete continuity and consistency between what He says and He does. As Vatican II teaches ("Dei Verbum", 2) Revelation is realized by deeds and words intimately connected with each other: the words proclaim the deeds and clarify the mystery contained in them; the deeds confirm the teaching. In this way Jesus progressively reveals the mystery of His Person: first the people sense His exceptional authority; later on, the Apostles, enlightened by God's grace, recognize the deepest source of this authority: "You are the Christ, the Son of the living God" (Matthew 16:16).]
[The note on Mk 3:14-19 states:
14-19. The Twelve chosen by Jesus (cf. 3:14) receive a specific vocation to be "people sent out", which is what the word "apostles" means. Jesus chooses them for a mission which He will give them later (6:6-13) and to enable them to perform this mission He gives them part of His power. The fact that He chooses "twelve" is very significant. This is the same number as the twelve Patriarchs of Israel, and the Apostles represent the new people of God, the Church founded by Christ. Jesus sought in this way to emphasize the continuity that exists between the Old and New Testaments. The Twelve are the pillars on which Christ builds His Church (cf. Gal 2:9); their mission to make disciples of the Lord (to teach) all nations, sanctifying and governing the believers (Mt 28:16-20; Mk 16:15; Lk 24:45-48; Jn 20:21-23).]
8-9. Jesus requires them to be free of any form of attachment if they are to preach the Gospel. A disciple, who has the mission of bringing the Kingdom of God to souls through preaching, should not rely on human resources but on God's Providence. Whatever he does not in order to live with dignity as a herald of the Gospel, he must obtain from those who benefit from his preaching, for the laborer deserves his maintenance (cf. Mt 10:10).
"The preacher should so trust in God that he is convinced that he will have everything he needs to support life, even if he cannot himself obtain it; for he should not neglect eternal things worrying about temporal things" (St Bede, "In Marci Evangelium Expositio, in loc."). "By these instructions the Lord did not mean that the evangelists should not seek to live in any other way than by depending on what was offered to them by those to whom they preached the Gospel; otherwise this very Apostle (St Paul) would have acted contrary to this precept when he earned his living by the labors of his own hands" (St Augustine, "De Consensu Evangelistarum", II, 30).
13. St Mark is the only evangelist who speaks of anointing the sick with oil. Oil was often used for treating wounds (cf. Is 1:6; Lk 10:34), and the Apostles also use it for the miraculous cure of physical illnesses by virtue of the power given them by Jesus. Hence the use of oil as the matter of the sacrament of the Anointing of the Sick, which cures wounds of the soul and even, if appropriate, bodily diseases. As the Council of Trent teaches--"Doctrina De Sacramento Extremae Unctionis", chap. 1--in this verse of St Mark there can be seen a "hint" of the sacrament of the Anointing of the Sick, which our Lord will institute and which later on "is recommended and promulgated to the faithful by St James the Apostle" (cf. Jas 5:14ff).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.