Mark 9:11-13

11And they asked him, saying, The scribes say that Elijah must first come.

12And he said unto them, Elijah indeed cometh first, and restoreth all things: and how is it written of the Son of man, that he should suffer many things and be set at nought?

13But I say unto you, that Elijah is come, and they have also done unto him whatsoever they listed, even as it is written of him.