Shake off the dust (ektinaxate ton koniorton). Shake out, a rather violent gesture of disfavour. The Jews had violent prejudices against the smallest particles of Gentile dust, not as a purveyor of disease of which they did not know, but because it was regarded as the putrescence of death. If the apostles were mistreated by a host or hostess, they were to be treated as if they were Gentiles (cf. Matthew 18:17 ; Acts 18:6 ). Here again we have a restriction that was for this special tour with its peculiar perils.