Charles Ellicott Commentary Matthew 17:10

"And his disciples asked him, saying, Why then say the scribes that Elijah must first come?" — Matthew 17:10 (ASV)

His disciples asked him —The context clearly implies that the question came not from the disciples in general, but from the three who had seen the vision. They were brooding over the appearance, and perhaps even more, the disappearance of Elijah, in connection with the tradition of the scribes. If Elijah was to come and prepare the way, why had he come in this way from the unseen world for only a moment?