Luke 9:28-31

Now about eight days after these teachings, He took along Peter and John and James and went up on the mountain to pray. [Matt 17:1-8; Mark 9:2-8] As He was praying, the appearance of His face became different [actually transformed], and His clothing became white and flashing with the brilliance of lightning. And behold, two men were talking with Him; and they were Moses and Elijah, who appeared in glory, and were speaking of His departure [from earthly life], which He was about to bring to fulfillment at Jerusalem.