“If any place

Will not welcome you,

If they refuse

To hear you,

As you leave,

Shake off the dust

That is on your feet

As a testimony

Against them.”

καὶ ὃς ἂν τόπος μὴ δέξηται ὑμᾶς μηδὲ ἀκούσωσιν ὑμῶν, ἐκπορευόμενοι ἐκεῖθεν ἐκτινάξατε τὸν χοῦν τὸν ὑποκάτω τῶν ποδῶν ὑμῶν εἰς μαρτύριον αὐτοῖς.

Equivalent passages to this can be found in Matthew, chapter 10:14, and Luke, chapter 9:5.  Mark indicated that Jesus said that if any place (καὶ ὃς ἂν τόπος) would not receive them (μὴ δέξηται ὑμᾶς) or listen to their words (μηδὲ ἀκούσωσιν ὑμῶν), they were to leave that place (ἐκπορευόμενοι ἐκεῖθεν).  They should shake off the dust from their feet (ἐκτινάξατε τὸν χοῦν τὸν ὑποκάτω τῶν ποδῶν ὑμῶν), as a witness or testimony against them (εἰς μαρτύριον αὐτοῖς).  This indicated that the dust of that house was useless.  Some orthodox texts have the statement about Sodom and Gomorrah that was in Matthew, chapter 10:15 that had Jesus make a comparison between the places that had rejected them with the famous wicked cities of Genesis, chapter 18:20-19:29, Sodom and Gomorrah.  He said with a solemn statement (ἀμὴν λέγω ὑμῖν) that it would be more tolerable (ἀνεκτότερον ἔσ) for the land of Sodom and Gomorrah (γῇ Σοδόμων καὶ Γομόρρων) on the judgment day (ἐν ἡμέρᾳ κρίσεως) than this place that rejected his disciples (ἢ τῇ πόλει ἐκείνῃ).  They had lacked hospitality to the followers of Jesus, so that they were worse than those terrible cities in Genesis.