Mark 9:10

7 And a cloud came over them; and a voice came out of the cloud, saying, This is my dearly loved Son, give ear to him.

8 And suddenly looking round about, they saw no one any longer, but Jesus only with themselves.

9 And while they were coming down from the mountain, he gave them orders not to give word to any man of the things they had seen, till the Son of man had come back from the dead.

10 And they kept the saying, questioning among themselves what the coming back from the dead might be.

11 And they put a question to him, saying, Why do the scribes say that Elijah has to come first?

12 And he said to them, Truly, Elijah does come first, and puts all things in order; and how is it said in the Writings that the Son of man will go through much sorrow and be made as nothing?

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.