Mark 9:32
But they did not understand what he meant and were afraid to ask him about it — the disciples' double failure: they do not understand, and they are afraid to ask. The fear of asking communicates that they sense the answer will be unwelcome — that pressing for clarity about the passion prediction will force them to engage with a reality they are avoiding. The not understanding after the second passion prediction is more culpable than after the first: they have had time, they have had the first prediction, and still the incomprehension persists.