{But they shook off the dust of their feet against them}
(Hoi de ektinaxamenoi ton koniorton t(936e) pod(936e) ep' autous).
First aorist middle (indirect) participle of ektinass(935c), to
shake out or off. Homer uses it for knocking out teeth. In the
papyri. The middle aorist participle occurs again in  18:6  and
the active imperative with the dust of the feet in  Mr 6:11  ( Lu
10:11  has apomassometha). and  Mt 10:14  (command of Jesus).
It is a dramatic gesture that forbids further intercourse. "As a
protest against the injustice which cast them out. The sandal was
taken off and the dust shaken out as a symbolic token that the
very soil of the country was defiling" (Furneaux). {Unto Iconium}
(eis Ikonion). About 45 miles southeast from Antioch in
Pisidia, at the foot of the Taurus mountains. At various times it
was reckoned also in Pisidia or Phrygia as well as Lycaonia,
Phrygian in population and distinguished by Luke ( Ac 14:6 ) from
Lystra and Derbe, cities of Lycaonia. As compared with Antioch (a
Roman colony) it was a native Phrygian town. When the province of
Galatia was divided, Iconium became the capital of Lycaonia and
eclipsed Antioch in Pisidia. Strictly speaking at this time
Lystra and Derbe were cities of Lycaonia-Galatica while Iconium
was in Phrygia-Galatica (all three in the Roman Province of
Galatia). It was at the meeting place of several Roman roads and
on the highway from east to west. It is still a large town Konieh
with 30,000 population.