After Peter’s confession, and before the road to Jerusalem. Mark says after six days.
Now. Mount Tabor is the traditional mountain. Mount Hermon has also been proposed, because it is nearer Caesarea Philippi, where the confession had just been made. The Church’s pilgrimage goes to Tabor. The event is the Father’s voice, not the altitude.Then. He takes Peter, James, and John. He is transfigured. Moses and Elijah appear. A voice says, This is my beloved Son, in whom I am well pleased: hear ye Him. He tells them to tell the vision to no one until the Son of man is risen.