Today's recounting of a moment of miracle and faith is found only in Luke. Part travelogue, part healing story, part pronouncement, this text slips and slides out of any one pinpoint identity. One of the most helpful ways to read today's pericope is in answer to the disciples' plea in 17:5, "Increase our faith." Jesus' series of hard sayings about discipleship in 17:1-10 demonstrate the surprising rules of followership while simultaneously revealing that Jesus' closest disciples are not yet ready for all that is about to come. In verses 11-19, a story of genuine faith unfolds right before the disciples' eyes. Yet the one who is proclaimed faithful is distinctly an outsider.

The text opens with Luke's familiar phrase "On the way to Jerusalem" (see also 9:51; 13:31-35). Although Jesus takes …