Luke 9:27-29

Young's Literal Translation

²⁷ and I say to you, truly, there are certain of those here standing, who shall not taste of death till they may see the reign of God.'

²⁸ And it came to pass, after these words, as it were eight days, that having taken Peter, and John, and James, he went up to the mountain to pray,

²⁹ and it came to pass, in his praying, the appearance of his face became altered, and his garment white -- sparkling.