Mark 9:28

28 After He went into a house, His disciples asked Him privately, "Why couldn't we drive 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 Then it came out, shrieking and convulsing him violently. The boy became like a corpse, so that many said, "He's dead."

27 But Jesus, taking him by the hand, raised him, and he stood up.

28 After He went into a house, His disciples asked Him privately, "Why couldn't we drive it out?"

29 And He told them, "This kind can come out by nothing but prayer [and fasting]."

30 Then they left that place and made their way through Galilee, but He did not want anyone to know it.