Jesus walked with His disciples from Bethsaida to the neighborhood of Caesarea Philippi. Six to eight days later, Jesus went up into a high mountain to pray, taking Peter, James, and John with Him and leaving His other nine disciples behind. There He was transfigured before the three. Meanwhile in the valley, the remaining nine disciples failed to cast out a demon from a young boy. Descending the day following His transfiguration, Christ healed the demoniac boy.
The failure of the nine disciples had given the scribes fuel for criticism of both the disciples and Christ. When Christ arrived on the scene, the scribes were being critically disruptive about the failure. The scribes were not known for their questioning as much as for their refuting and disputing. "Questioning" (KJV) or "disputing" (NKJV) in Mark 9:14 is translated from a Greek word that implies confuting, that is, attempting to disprove or deny.
The success of Christ, however, countered the failure of the disciples, shutting the mouths of the critical scribes. His coming upon this scene of dispute, chaos, and darkness must have been an incredible contrast to the honor, power, and glory that He had just experienced on the mountain in the Transfiguration. The sights and sounds that met Him on His return to the sinful world must have disturbed Him.
Martin G. Collins
The Miracles of Jesus Christ: Exorcising a Young Boy (Part One)