{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.  Mt 18:17  Ac 18:6 ). Here again we have
a restriction that was for this special tour with its peculiar
perils.