The Silence of Zachariah

Ἡ Ζαχαρῖου κώφευσις οὐκ ἐκπλήξει γέγονεν, ὡς ἐνόμισας, νουνεχέστατε. Ἐν συνηθείᾳ γὰρ θεοφανείας καὶ ἀγγελικῆς ὁσπτασίας ἥν ὁ ἱερεὺς, καθαρῶς τοῖς μυστηρίοις διακονούμενος, ἀλλὰ τῷ τύπῳ τῆς ἐκείνου σιγῆς, ἡ τοῦ νόμου ἐδηλοῦτο σιωπή. Τὸ δὲ ἀπὸ σιγῆς καὶ στειρώσεως, καὶ γήρως τεχθῆναι τὴν φωνὴν, τοῦτο οἴμαι δηλοῠν, τὸ ἐκ τοῦ παλαιωθέντος καὶ καταγηράσαντος στειρωθέντος, τῇ ἀνηκοῖα τῶν δεξαμένων νόμου τοῦ γραπτοῦ, τὰς περὶ Χριστοῦ προῥῥήσεις προελθεῖν, καὶ τὴν αὐτοῦ μητέρα ἐκ τούτου συνελθεῖν.     Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλιον Πρῶτον, Ἐπιστολή ΡΛΑ', Τιμοθεῳ Αναγνωστῃ

The muteness of Zachariah was not on account of fear, so you should judge, most prudent man, for in his priestly office, during his service of the mysteries, he was accustomed to theophanies and angelic visions, but rather it is a type of silence signifying the silence of the law. In the silence and barrenness, both of the working of an aged voice and the struggles of unfruitful aging, I think is made clear the disobedience of those who had received the written law, these things foretelling Christ's advent and his mother's meeting. Saint Isidore of Pelusium, Book 1, Letter 131, to the Lector  Timotheus