Mk 6:7-13
7[Jesus] summoned the Twelve and began to send them out two by two and gave them authority over unclean spirits. 8He instructed them to take nothing for the journey but a walking stick—no food, no sack, no money in their belts. 9They were, however, to wear sandals but not a second tunic. 10He said to them, “Wherever you enter a house, stay there until you leave from there. 11Whatever place does not welcome you or listen to you, leave there and shake the dust off your feet in testimony against them.” 12So they went off and preached repentance. 13They drove out many demons, and they anointed with oil many who were sick and cured them.
SHAKE THE DUST OFF YOUR FEET: The Jewish institution of the shaliach (“sent” in Hebrew) acknowledges that “the one sent is as the man who commissioned him.” Hence, the Twelve have the authority of Jesus behind them, an authority that demands of the disciples a rigorous commitment and of the villagers hospitality to the representatives of Jesus. Jesus’ instructions to the Twelve (apostles) to preach the gospel imply that they will be given hospitality, but also contain an ominous note that in some cases their word will not be tolerated. In this situation, they are to shake the dust off their feet as a testimony and warning to the inhospitable villagers.
The gesture of shaking the dust reflects the custom of pious Jews who had travelled outside of Israel. They remove carefully the dust from their feet and clothing so that nothing of the alien lands sticks to them. In shaking the dust, pious Jews dissociate themselves from the pollution of those lands and the judgment that is in store for foreign people.
The removal of dust from the feet on the part of Jesus’ disciples declares that the villages who do not receive them and the gospel are like pagans in character. The action is symbolic and provides a warning to the rejecting villagers. The disciples are fulfilling their responsibility as messengers of God, and those who will reject them will answer to God. In shaking the dust from their feet, the disciples are breaking communication with the villagers and consigning them to the judgment of God. The gesture is not a curse but is meant to make the inhabitants think again about what they have done and to lead them to repentance.