Mark 9:28

28 When he had entered the house, his disciples asked him privately, "Why could we not cast it 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 After crying out and convulsing him terribly, it came out, and the boy was like a corpse, so that most of them said, "He is dead."

27 But Jesus took him by the hand and lifted him up, and he was able to stand.

28 When he had entered the house, his disciples asked him privately, "Why could we not cast it out?"

29 He said to them, "This kind can come out only through prayer."

30 They went on from there and passed through Galilee. He did not want anyone to know it;