Charles Spurgeon Commentary 2 Peter 1:15-18

"Yea, I will give diligence that at every time ye may be able after my decease to call these things to remembrance. For we did not follow cunningly devised fables, when we made known unto you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty. 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: and this voice we [ourselves] heard borne out of heaven, when we were with him in the holy mount." — 2 Peter 1:15-18 (ASV)

Moreover, I will endeavour that you may be able after my decease to have these things always in remembrance. For we have not followed cunningly devised fables, when we made known to you the power and coming of our Lord Jesus Christ, but were eyewitnesses of his majesty.

For he received from God the Father honour and glory, when there came such a voice to him from the excellent glory, This is my beloved Son, in whom I am well pleased. And this voice which came from heaven we heard, when we were with him in the holy mount. Peter and James and John were with Christ on the Mount of Transfiguration, and Peter here bears his witness that they were not deceived when they bowed down before Christ, and worshipped him as Lord, nor were they deluded in expecting his coming and believing in his power.