Mark 9:2-9

Six days later, Jesus took with Him Peter and James and John, and led them up on a high mountain by themselves. And He was transfigured (changed in form) before them [and began to shine brightly with divine and regal glory]; [Matt 17:1-8; Luke 9:28-36] and His clothes became radiant and dazzling, intensely white, as no launderer on earth can whiten them. Elijah appeared to them along with Moses, and they were having a conversation with Jesus. Peter responded and said to Jesus, “Rabbi (Master), it is good for us to be here; let us make three [sacred] tents—one for You, and one for Moses, and one for Elijah.” For he did not [really] know what to say because they were terrified [and stunned by the miraculous sight]. Then a cloud formed, overshadowing them, and a voice came out of the cloud, “This is My beloved Son. Listen to Him and obey Him!” Suddenly they looked around and no longer saw anyone with them, except Jesus alone. As they were coming down from the mountain, Jesus expressly ordered them not to tell anyone what they had seen, until the Son of Man had risen from the dead.