Mark 9:2-13

²And after six days Jesus taketh with him Peter, and James, and John, and bringeth them up into a high mountain apart by themselves: and he was transfigured before them; ³and his garments became glistering, exceeding white, so as no fuller on earth can whiten them. ⁴And there appeared unto them Elijah with Moses: and they were talking with Jesus. ⁵And Peter answereth and saith to Jesus, Rabbi, it is good for us to be here: and let us make three tabernacles; one for thee, and one for Moses, and one for Elijah. ⁶For he knew not what to answer; for they became sore afraid. ⁷And there came a cloud overshadowing them: and there came a voice out of the cloud, This is my beloved Son: hear ye him. ⁸And suddenly looking round about, they saw no one any more, save Jesus only with themselves.

⁹And as they were coming down from the mountain, he charged them that they should tell no man what things they had seen, save when the Son of man should have risen again from the dead. ¹⁰And they kept the saying, questioning among themselves what the rising again from the dead should mean. ¹¹And they asked him, saying, [How is it] that 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 would, even as it is written of him.