I’m struggling to understand something in Matt. 17:17. The sick boy’s father told Jesus that he brought his son to His disciples earlier but they couldn’t help him. In verse 17 I’m not sure whether Jesus is talking to the crowd or to His disciples with that sharp tone of voice. I can’t imagine Jesus talking like that to his disciples in the midst of the crowd hence my doubt that he is talking to them. Do you think Jesus was talking to the crowd or to the disciples here? And if He was talking to the disciples then was He referring to the 9 or to the 3 he took to the mountain earlier?
When the Bible offers multiple accounts of an event it’s good to read them all to gain a more complete understanding. Mark’s account of this incident (Mark 9:14-27) tells us there were some Pharisees there who were arguing with the disciples. From the context, it appears the argument concerned the boy’s healing. Since the Jews had a formal procedure for exorcism, the Pharisees most likely questioned the disciples authority and/or ability to perform the healing. The uneducated disciples would have been intimidated, suffered a lapse of faith, and thus were unable to heal the boy. I don’t think Jesus was rebuking the disciples at all but was addressing His criticism to the Pharisees. Then He drove out the evil spirit to show them their procedure was unnecessary, that faith in God’s healing power is sufficient.