Matthew 17:10-13

And His disciples asked Him, “Why then do the scribes say that Elijah must come first?” And He answered and said, “Elijah is coming and will restore all things; but I say to you that Elijah already came, and they did not recognize him, but did to him whatever they wished. So also the Son of Man is going to suffer at their hands.” Then the disciples understood that He had spoken to them about John the Baptist.