Mark 9:5-10

And Peter said to Jesus, “Rabbi, it is good that we are here. Let us make three tents, one for you and one for Moses and one for Elijah.” For he did not know what to say, for they were terrified. And a cloud overshadowed them, and a voice came out of the cloud, “This is my beloved Son; listen to him.” And suddenly, looking around, they no longer saw anyone with them but Jesus only. And as they were coming down the mountain, he charged them to tell no one what they had seen, until the Son of Man had risen from the dead. So they kept the matter to themselves, questioning what this rising from the dead might mean.