The Gospel According to Matthew 17:10-18
At that time, the disciples asked Jesus, "Then why do the scribes say that first Elijah must come?" He replied, "Elijah does come and he is to restore all things; but I tell you that Elijah has already come, and they did not know him, but did to him whatever they pleased. So also the Son of man will suffer at their hands." Then the disciples understood that he was speaking to them of John the Baptist. And when they came to the crowd, a man came up to him and kneeling before him said, "Lord, have mercy on my son, for he is an epileptic and he suffers terribly; for often he falls into the fire, and often into the water. And I brought him to your disciples, and they could not heal him." And Jesus answered, "O faithless and perverse generation, how long am I to be with you? How long am I to bear with you? Bring him here to me." And Jesus rebuked him, and the demon came out of him, and the boy was cured instantly.