A.T. Robertson 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 (λαβων γαρ). Second aorist active participle nominative singular of λαμβανω, "he having received," but there is no finite verb, anacoluthon, changing in verse 19 (after parenthesis in 18) to εχομεν βεβαιοτερον rather than εβεβαιωσεν.

When there came such a voice to him (φωνης ενεχθεισης αυτω τοιασδε). Genitive absolute with first aorist passive participle feminine singular of φερω (cf. 1 Peter 1:13), repeated ενεχθεισαν in verse 18. Φωνη (voice) is used also of Pentecost (Acts 2:6). Τοιοσδε (classical demonstrative) occurs here alone in the N.T.

From the excellent glory (υπο της μεγαλοπρεπους δοξης). "By the majestic glory." Μεγαλοπρεπης, old compound (μεγας, great, πρεπε, it is becoming), here only in N.T., several times in O.T., Apocr. (II Macc. 8:15), adverb in the inscriptions. Probably a reference to νεφελη φωτεινη (bright cloud, shekinah) in Mt 17:5. The words given here from the "voice" agree exactly with Mt 17:5 except the order and the use of εις ον rather than εν ω. Mark and Luke (Luke 9:35) have ακουετε. But Peter did not need any Gospel for his report here.