Matthew 17:19
Then the disciples came to Jesus privately and said: why could we not cast it out? The private question — why could we not cast it out — is the disciples' honest engagement with their own failure. The willingness to ask the question rather than rationalize the failure communicates the disciples' genuine desire to understand. The private asking is the same pattern as the private asking about the parables (Matthew 13:10): the disciples press Jesus for understanding that they cannot reach on their own.