Barking and Blasphemy

Εἰ βλάψει κύων ὑλακτῶν γίγαντα δυσμαχώτατον, βλάψει καὶ τὸν ἀληθῆ πιστὸν πνεῦμα τῆς βλασφημίας, παρενοχλοῦν τῇ ψυχῇ. Ἅγιος Νειλος, Βιβλιον Πρῶτον, Ἐπιστολὴ ΤΙΓ' Θεσσαλιῳ Διακονῳ Source: Migne PG 79.196d

If a large dog harms by wearing one down grievously with his barking, so truly the spirit of blasphemy harms the faith, exhausting the soul. Saint Nilus of Sinai, Book 1, Letter 313, to Thessalius Deacon