Luke 9:28-31

28Now about eight days after these teachings, He took along Peter and John and James and went up on the mountain to pray.

29As He was praying, the appearance of His face became different [actually transformed], and His clothing became white and flashing with the brilliance of lightning.

30And behold, two men were talking with Him; and they were Moses and Elijah,

31who appeared in glory, and were speaking of His departure [from earthly life], which He was about to bring to fulfillment at Jerusalem.