Letting Down One's Guard

Πόθεν, ἔφης, οἱ πονηροὶ ἐκ τῆς καρδίας ἐξέρχονται, καὶ κοινοῦσι τὸν ἄνθρωπον; Ἐκ τοῦ καθεύδειν τοὺς γεωργοὺς ἐγρηγορέναι· ὀφείλοντας, καὶ φυλάττειν τοῦ καλοῦ σπέρματος τὸν καρπὸν ἀναθάλλοντα. Εἰ γὰρ μὴ κόρῳ καὶ κάρῳ τὴν ἑαυτῶν φυλακὴν προδεδώκειμεν, τὴν θείαν εἰκόνα μολύναντες, τουέστι τὸ καλὸν σπέρμα νοθεύσαντες, ὁ τῶν ζιζανίων σπορεὺς οὐκ ἂν εὖρε παρείαδυσιν, καὶ ἄξια πυρὸς ζιζάναι ἐν ἡμῖν κατειργάσατο. Ἅγιος Ἰσίδωρος Του Πηλουσιώτου, Βιβλίον Πρῶτον, Ἐπιστολή ΡϟΔ', Ὠριονι Μονακῳ Source: Migne PG 78.305d-308a

Whence, you say, comes wickedness from the heart to speak to men? From the slumber of the farmers it is made, they who should be guarding the fruit that has sprung up from good seed. For if we have not guarded ourselves from indolence and sleep beforehand, the Divine image is contaminated, that is, the good seed is debased, and the sower of weeds is not discovered by watching, and the weeds worthy of fire are thrust deep within us. Saint Isidore of Pelusium, Book 1, Letter 194, to the Monk Orion