“The dust is to be shaken off your feet lest when the dryness of barren unbelief crumbles the sole of your mind it is stained as if by a dry and sandy soil. A preacher of the gospel must take on himself the bodily weaknesses of a faithful people, so to speak. He must lift up and remove from his own soles worthless actions as if they were dust.”
- Ambrose of Milan, 333-397