Luke 9:28-31; Mark 9:9-13

Now about eight days after these sayings he took with him Peter and John and James and went up on the mountain to pray. And as he was praying, the appearance of his face was altered, and his clothing became dazzling white. And behold, two men were talking with him, Moses and Elijah, who appeared in glory and spoke of his departure, which he was about to accomplish at Jerusalem.

And as they were coming down the mountain, he charged them to tell no one what they had seen, until the Son of Man had risen from the dead. So they kept the matter to themselves, questioning what this rising from the dead might mean. And they asked him, “Why do the scribes say that first Elijah must come?” And he said to them, “Elijah does come first to restore all things. And how is it written of the Son of Man that he should suffer many things and be treated with contempt? But I tell you that Elijah has come, and they did to him whatever they pleased, as it is written of him.” (ESV)