The quotation made by Peter is very similar to the words found in Matthew 17:5, though there are slight differences. The declaration from the Father alludes to Psalm 2:7 and Isaiah 42:1. They point to the essence of Christ’s person and mission as the one who is both the King who rules and the Servant who would suffer and die for human sin.1 The transfiguration was thus to be seen as God’s appointment of Jesus as the eschatological vice-regent, a fulfillment especially of the prophecy made in Psalm 2:1–12. Jesus has been given the task of subduing the rebellious world to divine rule (Psalm 2:8–9) and he will exercise this task in the future when he comes in glory as the eschatological Judge and Ruler.2 Thus even as the heretics deny a final judgment, Peter presents the transfiguration as proof that Jesus has already been invested with the authority to judge the nations.3
17 For when he received honor and glory from God the Father, and the voice was borne to him by the Majestic Glory, “This is my beloved Son, with whom I am well pleased,”