John Gill emphasizes the significance of the voice from heaven heard by Peter, James, and John during the Transfiguration of Christ, which confirmed Jesus' divine glory and authority. This event served as a powerful testimony to the apostles, affirming their faith in Christ's future return in power and glory. Gill explains that the 'holy mount' refers to the mountain where this divine revelation occurred, highlighting the sacredness of the moment. The apostles were not only witnesses to this miraculous event but were also compelled to share the truth of Christ's power and coming based on both their experience and the prophetic word. This sermon encourages believers to trust in the certainty of Christ's return, grounded in both personal experience and Scripture.

Ver. 18. And this voice, which came from heaven, we heard,.... Peter, who wrote this epistle, and James and John, the favourite disciples of Christ; and who were a sufficient number to bear witness of what they then saw and heard: when we were with him; and saw his glory, and the glory of Moses and Elias, and were so delighted with his company, and theirs, and with communion with him, that Peter, in the name of the rest, desired to stay there: in the holy mount; the Ethiopic version reads, "in the mountain of his sanctuary"; and so Grotius understands it of Mount Moriah, on which the temple was built, called the holy hill, and the holy hill of Zion; and supposes that this voice was heard in the temple, and that it refers to Joh 12:28, but without any foundation; for the mount on which Christ was transfigured is here meant; and which was either, as is generally said, Tabor, a mountain in Galilee; or it may be Lebanon, which was near Caesarea Philippi, in the parts of which Christ then was: and it is called "holy", from his presence or transfiguration on it, who is the Holy One; just as the land on which Moses was, and the city and temple of Jerusalem, and Mount Sion, and Sinai, are called "holy", from the presence of the holy God there, Ex 3:5. Now such a declaration of the honour and glory of Christ, as the Son of God, being made by God the Father, in a voice from heaven, which the apostles heard with their ears, at the same time that they saw with their eyes his human body glorified in an amazing manner, was to them a confirming evidence that he would come again in power and glory; and upon this evidence they declared, and made known to the saints, the power and coming of Christ; though not on this evidence only, but also upon the more sure word of prophecy, which entirely agrees with it.