Mark 9:16

But I tell you that Elijah has come, and they have also done to him whatever they wanted to, even as it is written about him.”

Coming to the disciples, he saw a great multitude around them, and scribes questioning them.

Immediately all the multitude, when they saw him, were greatly amazed, and running to him, greeted him.

One of the multitude answered, “Teacher, I brought to you my son, who has a mute spirit;

and wherever it seizes him, it throws him down; and he foams at the mouth, grinds his teeth, and becomes rigid. I asked your disciples to cast it out, and they weren’t able.”

He answered him, “Unbelieving generation, how long shall I be with you? How long shall I bear with you? Bring him to me.”