Melito of Sardis, Fragment on the Incarnation
Those who have understanding need no proof drawn from what Christ did after his baptism to demonstrate the true and invisible reality of his soul and body, of our human nature. For the works he performed after his baptism, and especially the signs, revealed his deity hidden in flesh and convinced the world. Since he was God and perfect man together, the same one confirmed to us his two natures: his deity through the signs during the three years after his baptism, and his humanity during the thirty years before his baptism, when, because of the imperfection belonging to the flesh, he concealed the signs of his deity, even though he existed as the true, pre‑existent God.
Greek
Οὐδεμία ἀνάγκη τοῖς νοῦν ἔχουσιν, ἐξ ὧν μετὰ τὸ βάπτισμα ὁ Χριστὸς ἔπραξε, παριστᾶν τὸ ἀληθὲς καὶ ἀφανταστὸν τῆς ψυχῆς αὐτοῦ καὶ τοῦ σώματος, τῆς καθ' ἡμᾶς ἀνθρωπίνης φύσεως. Τὰ γὰρ μετὰ τὸ βάπτισμα ὑπὸ Χριστοῦ πραχθέντα, καὶ μάλιστα τὰ σημεῖα, τὴν αὐτοῦ κεκρυμμένην ἐν σαρκὶ θεότητα ἐδήλουν, καὶ ἐπιστοῦντο τῷ κόσμῳ. Θεὸς γὰρ ὢν ὁμοῦ τε καὶ ἄνθρωπος τέλειος ὁ αὐτὸς τὰς δύο αὐτοῦ οὐσίας ἐπιστώσατο ἡμῖν, τὴν μὲν θεότητα αὐτοῦ διὰ τῶν σημείων ἐν τῇ τριετίᾳ τῇ μετὰ τὸ βάπτισμα, τὴν δὲ ἀνθρωπότητα αὐτοῦ ἐν τοῖς τριάκοντα χρόνοις τοῖς πρὸ τοῦ βαπτίσματος, ἐν οἷς διὰ τὸ ἀτελὲς τὸ κατὰ σάρκα ἀπέκρυβε τὰ σημεῖα τῆς αὐτοῦ θεότητος, καίπερ θεὸς ἀληθὴς προαιώνιος ὑπάρχων.