Then came the disciples to Jesus apart, and said, Why could not we cast him out?
Ver. 19. Why could not we cast him out?] They had heard why before, but either heeded it not or were not willing to hear on that ear. Loth they were to yield that it was any fault of theirs, that the cure was not effected by them, but by some other occasion (the father's faithlessness, the people's perverseness, &c.), which what it was, here they make inquiry. How unwilling are we that our penny should be held other than good silver! How ready to shift off him that speaks from heaven, παραιτησησθε , Heb 12:25 and to mistake ourselves in the causes of our miscarriages!