Now it came to pass, about eight days after these sayings, that He took Peter, John, and James and went up on the mountain to pray.
As He prayed, the appearance of His face was altered, and His robe became white and glistening.
And behold, two men talked with Him, who were Moses and Elijah,
who appeared in glory and spoke of His decease which He was about to accomplish at Jerusalem.
But Peter and those with him were heavy with sleep; and when they were fully awake, they saw His glory and the two men who stood with Him.
Luke 9:28-32
(NKJV)