Matthew 17:2
1 Six days later Jesus took with him Peter, James, and John the brother of James, and led them privately up a high mountain. 2 And he was transfigured before them. His face shone like the sun, and his clothes became white as light. 3 Then Moses and Elijah also appeared before them, talking with him. 4 So Peter said to Jesus, “Lord, it is good for us to be here. If you want, I will make three shelters—one for you, one for Moses, and one for Elijah.”
2 Baruch 51:3
Syriac Apocalypse of Baruch1 And it shall come to pass, when that appointed day has gone by, that then shall the aspect of those who are condemned be afterwards changed, and the glory of those who are justified. 2 For the aspect of those who now act wickedly shall become worse than it is, as they shall suffer torment. 3 Also (as for) the glory of those who have now been justified in My law, who have had understanding in their life, and who have planted in their heart the root of wisdom, then their splendour shall be glorified in changes, and the form of their face shall be turned into the light of their beauty, that they may be able to acquire and receive the world which does not die, which is then promised to them. 4 For over this above all shall those who come then lament, that they rejected My law, and stopped their ears that they might not hear wisdom or receive understanding. 5 When therefore they see those, over whom they are now exalted, (but) who shall then be exalted and glorified more than they, they shall respectively be transformed, the latter into the splendour of angels, and the former shall yet more waste away in wonder at the visions and in the beholding of the forms.
Notes and References
"... Matthew 17:2 ... Moses' face shone because it reflected something of God's glory (Exodus 34:29--30). But as for Jesus, he himself was transfigured. The verb metamorphoo ('transfigure,' 'transform,' 'change in form') suggests a change of inmost nature that may be outwardly visible (as here; compare Exodus 34:29; 2 Baruch 51:3-5) or quite invisible (Romans 12:2; 2 Corinthians 3:18). That Jesus was transfigured 'before them' implies that it was largely for their sakes: whatever confirmation the experience may have given Jesus, for the disciples it was revelatory. As they would come to realize, they were being privileged to glimpse something of his preincarnate glory (John 1:14; 17:5; Philippians 2:6-7) and anticipate his coming exaltation (2 Peter 1:16-18; Revelation 1:16). Their confession of Jesus as Messiah and his insistence that he would be a suffering Messiah (16:13-21; 17:9) were confirmed. Therefore they had reason to hope that they would yet see the Son of Man coming in his kingdom (16:28). The contrast between what Jesus had just predicted would be his fate (16:21) and this glorious sight would one day prompt Jesus' disciples to marvel at the self-humiliation that brought him to the cross and to glimpse a little of the height to which he had been raised by his vindicating resurrection and ascension ..."
Gaebelein, Frank Ely The Expositor’s Bible Commentary: Matthew, Mark, Luke (p. 385) Pickering & Inglis, 1984