John Wesley on Mark 8:17-18

Our Lord here affirms of all the apostles, (for the question is equivalent to an affirmation,) That their hearts were hardened; that having eyes they saw not, having ears they heard not; that they did not consider, neither understand: the very same expressions that occur in the thirteenth of Matthew. And yet it is certain they were not judicially hardened. Therefore all these strong expressions do not necessarily import any thing more than the present want of spiritual understanding.