In his Angelus address, Pope Benedict spoke on the Transfiguration. From Zenit:
Dear Brothers and Sisters:
On this Second Sunday of Lent, the Evangelist Luke underlines that Jesus went up the mountain "to pray" (9:28) together with the apostles Peter, James and John and, "as he was praying" (9:29) the luminous mystery of his transfiguration took place.
For the three apostles, to go up on the mountain meant to be involved in Jesus' prayer, who often withdrew to pray, especially at dawn or after sundown, and sometimes during the whole night. However, on that occasion alone, on the mountain, he wished to manifest to his friends the interior light that invaded him when he prayed: His face -- we read in the Gospel -- his countenance was altered and his raiment became dazzling, reflecting the splendor of the divine person of the Incarnate Word (cf. Luke 9:29).
There is another detail in St. Luke's narrative which is worth underlining: It indicates the object of Jesus' conversation with Moses and Elijah, who appeared next to him when transfigured. The Evangelist narrates that they "spoke of his departure (in Greek, 'exodos'), which he was to accomplish at Jerusalem" (9:31).
Therefore, Jesus listens to the Law and the prophets that speak to him of his death and resurrection. In his intimate dialogue with his Father, he does not leave history, he does not flee from the mission for which he came into the world, though he knows that to attain glory he will have to go through the cross. What is more, Christ enters this mission more profoundly, adhering with all his being to the will of the Father, and he shows us that true prayer consists precisely in uniting our will to the Father's.
Therefore, for a Christian to pray is not to evade reality and the responsibilities it entails, but to assume them to the end, trusting in the faithful and inexhaustible love of the Lord. For this reason, the proof of the Transfiguration is, paradoxically, the agony in Gethsemane (cf. Luke 22:39-46). Given the imminence of the passion, Jesus experiences mortal anguish and entrusts himself to the divine will; at that moment his prayer is a pledge of salvation for us all. Christ, in fact, would implore the heavenly Father to "save him from death" and, as the author of the Letter to the Hebrews writes, "he was heard for his godly fear" (5:7). The Resurrection is proof that he was heard.
Dear Brothers and Sisters: Prayer is not something accessory, it is not "optional," but rather a question of life or death. Only one who prays, that is, who entrusts himself to God with filial love, can enter into eternal life, which is God himself. During this season of Lent, let us pray to Mary, mother of the Incarnate Word and teacher of the spiritual life, to teach us to pray as her Son did so that our life is transformed by the light of his presence.