But Jesus Only

Mark 9:4-8 ESV

4 And there appeared to them Elijah with Moses, and they were talking with Jesus. 5 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.” 6 For he did not know what to say, for they were terrified. 7 And a cloud overshadowed them, and a voice came out of the cloud, “This is my beloved Son; listen to him.” 8 And suddenly, looking around, they no longer saw anyone with them but Jesus only.

Peter's response places all three of those appearing before the disciples as equals. God then speaks, saying listen to my beloved Son. 

Then suddenly all they see is Jesus. 

ἐξάπινα * exapina * ex-ap'-ee- of a sudden, that is, unexpectedly: - suddenly
  out of nowhere

overshadowed

The same word is used here as when the Holy Spirit overshadowed Mary. 

ἐπισκιάζω * episkiazō * ep-ee-skee-ad'-zo *  to cast a shade upon, that is, (by analogy) to envelop in a haze of brilliancy; figuratively to invest with preternatural influence: - overshadow.

They give way to the Son as the Son is given. Listen to Him.