How is it that ye do not understand? A better reading here is οὔπω instead of πῶς ου). Therefore the words should run, Do ye not yet understand? It is as though our Lord said, "You ought to have perceived, both from my words and from my actions, that I was not speaking concerning earthly leaven or earthly bread, but concerning spiritual doctrine."
St. Matthew here (Matthew 16:12) is careful to tell us that this reproof of Christ quickened their intellects, and forced them to understand.