In the advise Jesus gave to the apostles when sending them off, there were three lines to which we might give special attention..
The first line to note is: “Without cost you have received, without cost you are to give.” That is akin to what Paul wrote in First Corinthians, 4:7 “What do you possess that you have not received.” Our bodies, our education, our positions all came to us free. Doesn’t that bind us to give freely of any benefits that came to us?
The second line is, “The laborer deserves his keep.” We must read that in conjunction with Jesus telling them not to bring money, food, or extra clothing. He wasn’t telling them to practice poverty. No, he was telling them to open themselves to the hospitality of the people. Having gained the right to be repaid for coming to them h was to mingle, not holing up with the TV in a Holiday Inn.
The third line is, “Go outside the house or town and shake the dust from your feet.”
There, Jesus may have been saying that our whole world, coming from God’s hands, is a holy place.
The reason for that interpretation is that the only time Jews were told to shake the dust from their feet was when they were entering the temple. The idea behind that was that the temple, like the burning bush in Exodus, was a holy place, not to be contaminated by dust from an impure world. Our Lord’s instruction to the Apostles reversed that consideration. He asked them to see the world as a holy place not to be contaminated by dust from an inhospitable town or house.