John Calvin Commentary 2 Peter 1:17

"For he received from God the Father honor and glory, when there was borne such a voice to him by the Majestic Glory, This is my beloved Son, in whom I am well pleased:" — 2 Peter 1:17 (ASV)

For he received from God the Father. He chose one memorable example out of many, specifically that of Christ, when, adorned with celestial glory, He conspicuously displayed His divine majesty to His three disciples. And though Peter does not relate all the circumstances, yet he sufficiently designates them when he says, that a voice came from the magnificent glory. For the meaning is that nothing earthly was seen there, but that a celestial majesty shone on every side. From this, we may conclude what those displays of greatness were which the evangelists relate. And this was necessarily done so that the authority of that voice which came might be more awe-inspiring and solemn, as we see was done by the Lord in that one instance. For when He spoke to the fathers, He did not only cause His words to sound in the air, but by adding some symbols or tokens of His presence, He proved the oracles to be His.

This is my beloved Son. Peter then mentions this voice as if it alone were sufficient evidence for the gospel, and rightly so. For when we acknowledge Christ to be the One whom the Father has sent, this is our highest wisdom. This sentence has two parts. When He says, “This is,” the expression is very emphatic, intimating that He was the Messiah who had been so often promised. Whatever, then, is found in the Law and the Prophets concerning the Messiah is declared here, by the Father, to belong to Him whom He so highly commended. In the other part of the sentence, He announces Christ as His own Son, in whom His whole love dwells and centers. It therefore follows that we are not loved otherwise than in Him, nor should the love of God be sought anywhere else. It is sufficient for me now only to touch on these things in passing.