Six days later Jesus took with Him Peter and James and John his brother, and led them up on a high mountain by themselves. And He was transfigured before them; and His face shone like the sun, and His garments became as white as light. And behold, Moses and Elijah appeared to them, talking with Him. Peter said to Jesus, "Lord, it is good for us to be here; if You wish, I will make three tabernacles here, one for You, and one for Moses, and one for Elijah." While he was still speaking, a bright cloud overshadowed them, and behold, a voice out of the cloud said, "This is My beloved Son, with whom I am well-pleased; listen to Him!" When the disciples heard this, they fell face down to the ground and were terrified. And Jesus came to them and touched them and said, "Get up, and do not be afraid." And lifting up their eyes, they saw no one except Jesus Himself alone. As they were coming down from the mountain, Jesus commanded them, saying, "Tell the vision to no one until the Son of Man has risen from the dead."
Matthew 17:1-9
Six days later, Jesus took with Him Peter and James and John, and brought them up on a high mountain by themselves. And He was transfigured before them; and His garments became radiant and exceedingly white, as no launderer on earth can whiten them. Elijah appeared to them along with Moses; and they were talking with Jesus. Peter said to Jesus, "Rabbi, it is good for us to be here; let us make three tabernacles, one for You, and one for Moses, and one for Elijah." For he did not know what to answer; for they became terrified. Then a cloud formed, overshadowing them, and a voice came out of the cloud, "This is My beloved Son, listen to Him!" All at once they looked around and saw no one with them anymore, except Jesus alone.
Mark 9:2-8
Some eight days after these sayings, He took along Peter and John and James, and went up on the mountain to pray. And while He was praying, the appearance of His face became different, and His clothing became white and gleaming. And behold, two men were talking with Him; and they were Moses and Elijah, who, appearing in glory, were speaking of His departure which He was about to accomplish at Jerusalem. Now Peter and his companions had been overcome with sleep; but when they were fully awake, they saw His glory and the two men standing with Him. And as these were leaving Him, Peter said to Jesus, "Master, it is good for us to be here; let us make three tabernacles: one for You, and one for Moses, and one for Elijah "-not realizing what he was saying. While he was saying this, a cloud formed and began to overshadow them; and they were afraid as they entered the cloud. Then a voice came out of the cloud, saying, "This is My Son, My Chosen One; listen to Him!" And when the voice had spoken, Jesus was found alone. And they kept silent, and reported to no one in those days any of the things which they had seen.
Luke 9:28-36
16 For we did not follow cleverly devised tales when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty. For when He received honor and glory from God the Father, such an utterance as this was made to Him by the Majestic Glory, "This is My beloved Son with whom I am well pleased "- and we ourselves heard this utterance made from heaven when we were with Him on the holy mountain.
2 Peter 1:16-18