But they shook off the dust of their feet against them (Hoi de ektinaxamenoi ton koniorton tōn podōn ep' autous). First aorist middle (indirect) participle of ektinassō, to shake out or off. Homer uses it for knocking out teeth. In the papyri. The middle aorist participle occurs again in Act 18:6 and the active imperative with the dust of the feet in Mar 6:11 (Luk 10:11 has apomassometha). and Mat 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 (Act 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.