Mark 9:9-13

9As they were coming down from the mountain, Jesus expressly ordered them not to tell anyone what they had seen, until the Son of Man had risen from the dead.

10So they [carefully and faithfully] kept the matter to themselves, discussing and questioning [with one another] what it meant to rise from the dead.

11They asked Him, saying, “Why do the scribes say that Elijah must come first [before the Messiah comes]?”

12He answered them, “Elijah does come first and restores and reestablishes all things. And yet how is it written of the Son of Man that He will suffer many things [grief and physical distress] and be treated with contempt [utterly despised and rejected]?

13But I say to you that Elijah has in fact come [already], and they did to him whatever they wished, just as it is written [in Scripture] of him.”