Mark 9:28

28 After arriving back home, his disciples cornered Jesus and asked, "Why couldn't we throw the demon out?"

Mark 9:28 Meaning and Commentary

Mark 9:28

And when he was come into the house
Perhaps into the man's house whose child he had healed, or into some other in these parts, for the sake both of retirement and refreshment:

his disciples asked him privately, why could not we cast him out?
The nine disciples, who were particularly concerned in this matter, fearing they had lost the power of casting out devils, conferred upon them, inquired of Jesus, when he was alone, why they could not cast the demon out of the child, when they had ejected unclean spirits out of many others; (See Gill on Matthew 17:19).

Mark 9:28 In-Context

26 Screaming, and with much thrashing about, it left. The boy was pale as a corpse, so people started saying, "He's dead."

27 But Jesus, taking his hand, raised him. The boy stood up.

28 After arriving back home, his disciples cornered Jesus and asked, "Why couldn't we throw the demon out?"

29 He answered, "There is no way to get rid of this kind of demon except by prayer."

30 Leaving there, they went through Galilee. He didn't want anyone to know their whereabouts,