Mark 9:28-32

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.

And they departed thence, and passed through Galilee; and he would not that any man should know it.

For he taught his disciples, and said unto them, The Son of man is delivered into the hands of men, and they shall kill him; and after that he is killed, he shall rise the third day.

But they understood not that saying, and were afraid to ask him.