In sending out his disciples Jesus gave them instructions that could hold for us as well. Those directions centered on how to behave with people who accepted them; then, on how to behave with those who did not accept them.
With those who did accept them, they were to behave like family, sitting down, and eating with everyone else, rather than being aloof, staying at a Holiday Inn.
Jesus, then told them how to behave when they received no welcome. He told them to shake the dust of that unwelcoming place off their feet.
With all of our streets and sidewalks paved, we don’t have any dust to shake off; but if we consult the way devout people in Jerusalem behaved back then, we can see how Our Lord’s instruction could have another meaning for us.
Back then, the one time people were told to shake the dust from their sandals was when they were about to enter the holy ground of Jerusalem’ temple. The ground where the temple stood was analogues to the ground where Moses came upon the burning bush. So, as they were entering the temple they would imagine God telling them, “Remove the sandals from your feet, for the place whereon you stand is holy ground.”
By an interesting reversal, on leaving an inhospitable town, the disciples would be shaking off that contaminated dust before going out into a world, all of which is holy. Jesus is telling us to look upon all the world as God’s own holy place.