Mark 9:14

And when he came to his disciples, he saw a great multitude about them, and the scribes questioning with them.

Cross-reference

Matthew 17:14-21 gives a parallel account of the same healing story, adding details about the disciples' lack of faith.

Luke 9:37 Parallel

Luke 9:37 is the synoptic parallel to this scene, describing the same crowd and the boy with an unclean spirit.