Mark 9:2-9 Revised Standard Version Catholic Edition (RSVCE)
2 And after six days Jesus took with him Peter and James and John, and led them up a high mountain apart by themselves; and he was transfigured before them, 3 and his garments became glistening, intensely white, as no fuller on earth could bleach them. 4 And there appeared to them Eli′jah with Moses; and they were talking to Jesus. 5 And Peter said to Jesus, “Master,[a] it is well that we are here; let us make three booths, one for you and one for Moses and one for Eli′jah.” 6 For he did not know what to say, for they were exceedingly afraid. 7 And a cloud overshadowed them, and a voice came out of the cloud, “This is my beloved Son;[b] listen to him.” 8 And suddenly looking around they no longer saw any one with them but Jesus only.
The Coming of Elijah
9 And as they were coming down the mountain, he charged them to tell no one what they had seen, until the Son of man should have risen from the dead.