Transfiguration and Resurrection

Ἡ ἐν τῷ ὅρει μεταμόρφωσις τοῦ Δεσπότου ὑμῶν καὶ Σωτῆρος, τὴν ἐκ νεκρῶν ἐξανάστασιν ἡμῶν προεδήλου, ἦντινα καὶ φυλάττειν ἐν ἑαυτοῖς οἱ θεατι προσετάτοντο μέχρι τῆς αὐτοῦ ἀναστάσεως, ὡς τότε πιστὴν φανησομένην, οἶα τῷ ἔργῳ ὁρωμένην. Ἡ δὲ Μωσέως καὶ Ἡλίου παρουσία, τὴν ζώτων καὶ νεκρῶν ἐμαρτύρησεν αὐτῷ δεσποτείαν. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλίον Πρῶτον, Ἐπιστολή ΣΛΘ', Αλφιῳ Πρεσβυτερῳ

The transfiguration of our Lord and Saviour on the mount is a foreshowing of our resurrection from the dead, which those who saw were to keep within themselves until his resurrection, so that the revelation of faith be in such a work seen. And the presence of Moses and Elijah bore witness to the Lord of the living and the dead. Saint Isidore of Pelusium, Book 1, Letter 239, to the Priest Alphius