Charles Spurgeon Commentary Mark 9:28-29

"And when he was come into the house, his disciples asked him privately, [How is it] that we could not cast it out? And he said unto them, This kind can come out by nothing, save by prayer." — Mark 9:28-29 (ASV)

And when he was come into the house, his disciples asked him privately, Why could not we cast him out? And he said unto them, This kind can come forth by nothing, but by prayer and fasting.

The watchword for Christ's disciples is "intensity." Here was the devil in an intensely terrible form, and he could only be driven out by intense grace. There must be prayer and fasting. Even Christ himself must exert the greatness of his power to work a cure in such a case as this. Oh, for more intensity in us all! Carry that word in your ear as we read on.