29 The crowd that was there and heard it said it had thundered; others said an angel had spoken to him.
30 Jesus said, "This voice was for your benefit, not mine."
A great miracle is here exhibited for the benefit of both the hearers and now the readers (which would be us) through the heavenly Voice described in these verses. A voice so loud that some who heard it proclaimed it was thunder while others presumed angelic vernacular. God constantly authenticated His Son for our benefit – confirming their relationship – pointing us to the Truth of the Savior. He did this through a myriad of ways, just as He continues to do for us today:
"When it comes to hearing from God, I firmly believe the Bible is our source and authority. God's Word is like a megaphone to His people. Throughout Scripture God speaks through kings and queens, princes and prophets, poets and pilgrims. He speaks through weather patterns, barnyard animals and even the stars in the sky. God is not only creative, but He is persistent in getting our attention and communicating with us.” Margaret Feinberg
“God’s Word, together with the whole character of God...settles all questions.” George Muller
This was the third time in Christ’s ministry that God’s wondrous voice was heard authenticating the Son by the Father. The first was at our Lord’s baptism at the beginning of His ministry when the heavens opened up and the Holy Spirit descended on Jesus like a dove:
16 As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and lighting on him. 17 And a voice from heaven said, "This is my Son, whom I love; with him I am well pleased." Matt 3:16-17 (NIV)
Again God’s voice was heard at the transfiguration where Jesus, accompanied by Peter, James and John, was transfigured before their eyes along with Moses and Elijah. This authentication of Jesus by the voice of God carried great significance to these disciples:
5 While he was still speaking, a bright cloud enveloped them, and a voice from the cloud said, "This is my Son, whom I love; with him I am well pleased. Listen to him!" 6 When the disciples heard this, they fell facedown to the ground, terrified. 7 But Jesus came and touched them. "Get up," he said. "Don't be afraid." 8 When they looked up, they saw no one except Jesus. Matt 17:5-8 (NIV)
These three apostles were privy to see Jesus in all His glory giving them a foretaste of heaven – something they would never forget. Yet even as wondrous as that sight would have been, Peter appeared to have been even more impressed by what he heard than by the glorious display he saw. The experience left such an impression that Peter later wrote regarding it in his second epistle:
16 We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty. 17 For he received honor and glory from God the Father when the voice came to him from the Majestic Glory, saying, "This is my Son, whom I love; with him I am well pleased." 18 We ourselves heard this voice that came from heaven when we were with him on the sacred mountain. 19 And we have the word of the prophets made more certain, and you will do well to pay attention to it, as to a light shining in a dark place, until the day dawns and the morning star rises in your hearts. 20 Above all, you must understand that no prophecy of Scripture came about by the prophet's own interpretation. 21 For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit. 2 Peter 1:16-21 (NIV)
When writing about this amazing transfiguration experience he was witness to, Peter was reminded of yet another form of God’s Word – the written Word – given through the prophets. The privilege of hearing God’s voice on the mountain and seeing Jesus, Moses and Elijah in their glorified states, made the prophetic written Word even more certain calling us to take heed and to pay attention to it as well.
4 For everything that was written in the past was written to teach us, so that through endurance and the encouragement of the Scriptures we might have hope. 5 May the God who gives endurance and encouragement give you a spirit of unity among yourselves as you follow Christ Jesus, 6 so that with one heart and mouth you may glorify the God and Father of our Lord Jesus Christ. Romans 15:4-6 (NIV)