Mark 9:16

13 But I say to you that Elijah has come, and they have done to him whatever they were pleased to do, even as the Writings say about him.

14 And when they came to the disciples, they saw a great mass of people about them, and scribes questioning them.

15 And straight away all the people, when they saw him, were full of wonder, and running to him, gave him worship.

16 And he said, What are you questioning them about?

17 And one of the number said to him in answer, Master, I came to you with my son, who has in him a spirit which takes away his power of talking;

18 And wherever it takes him, it puts him down violently, streaming at the lips and twisted with pain; and his strength goes from him; and I made a request to your disciples to send it out, and they were not able.

19 And he said to them in answer, O generation without faith, how long will I have to be with you? how long will I put up with you? let him come to me.