XII. (printed 'XII 1.' with §1)
Besides, I hold the words of the saints' prayer full of power — especially when praying they pray in spirit and with the mind: like light dawning from the pray-er's thought and proceeding from his mouth, by God's power dissolving the intelligible poison shot by opposing powers at the ruling part of those neglecting to pray and not keeping Paul's 'pray unceasingly,' spoken after Jesus' exhortations. For like an arrow from the pray-er's soul, with knowledge and word or faith, it goes forth from the holy one, wounding unto destruction the spirits hostile to God, who want to cast us into sin's bonds.
One prays unceasingly when works of virtue, or commandments performed, are taken up as part of prayer — joining prayer to needful works and befitting deeds to prayer. Only thus can we receive 'pray unceasingly' as possibly spoken: if we call the saint's whole life one continuous great prayer, of which the customarily-named prayer is part, owed no less than thrice daily — clear from Daniel, praying thrice a day with such danger hanging over him. And Peter going up to the roof to pray at the sixth hour, when he saw the vessel coming down from heaven let down by four corners, exhibits the middle of the three prayers: with before it the one spoken by David, 'In the morning You shall hear my prayer; in the morning I shall present myself to You and watch'; and the last shown by 'The lifting of my hands, an evening sacrifice.' Nor should we duly pass the night season without this prayer — with David saying, 'At midnight I rose to confess to You for Your righteous judgments,' and Paul, as Acts says, at midnight with Silas in Philippi praying and hymning God, so that even the prisoners overheard them.
Greek (GCS)
§1. Πρὸς δὲ τούτοις δυνάμεως πεπληρωμένους νομίζω τοὺς λόγους τῆς τῶν ἁγίων εὐχῆς, μάλιστα ὅτε προσευχόμενοι πνεύματι προσεύχονται καὶ τῷ νοΐ, φωτὶ ἐοικότι ἀνατέλλοντι ἀπὸ τῆς τοῦ εὐχομένου διανοίας καὶ προϊόντι ἐκ στόματος αὐτοῦ ὑπεκλύειν δυνάμει θεοῦ τὸν ἐνιέμενον νοητὸν ἰὸν ἀπὸ τῶν ἀντικειμένων δυνάμεων τῷ ἡγεμονικῷ τῶν ἀμελούντων τοῦ εὔχεσθαι καὶ τὸ ἀδιαλείπτως προσεύχεσθε ἀκολούθως ταῖς τοῦ Ἰησοῦ προτροπαῖς εἰρημένον παρὰ τῷ Παύλῳ μὴ φυλαττόντων. ὡσπερεὶ γὰρ βέλος ἀπὸ τῆς τοῦ εὐχομένου ψυχῆς τῇ γνώσει καὶ τῷ λόγῳ ἢ τῇ πίστει πρόεισιν ἀπὸ τοῦ ἁγίου, τιτρῶσκον ἐπὶ καθαιρέσει καὶ καταλύσει τὰ ἐχθρὰ τῷ θεῷ πνεύματα, τοῖς τῆς ἁμαρτίας δεσμοῖς περιβαλεῖν ἡμᾶς θέλοντα. §2. ἀδιαλείπτως δὲ προσεύχεται, καὶ τῶν ἔργων τῆς ἀρετῆς ἢ τῶν ἐντολῶν τῶν ἐπιτελουμένων εἰς εὐχῆς ἀναλαμβανομένων μέρος, ὃ συνάπτων τοῖς δέουσιν ἔργοις τὴν εὐχὴν καὶ τῇ εὐχῇ τὰς πρεπούσας πράξεις. οὕτω γὰρ μόνως τὸ ἀδιαλείπτως προσεύχεσθε ἐκδέξασθαι δυνάμεθα ὡς δυνατὸν ὃν εἰρημένον, εἰ πάντα τὸν βίον τοῦ ἁγίου μίαν συναπτομένην μεγάλην εἴποιμεν εὐχήν· ἧς εὐχῆς μέρος ἐστὶ καὶ ἡ συνήθως ὀνομαζομένη εὐχή, οὐκ ἔλαττον τοῦ τρὶς ἑκάστης ἡμέρας ἐπιτελεῖσθαι ὀφείλουσα· ὅπερ δῆλόν ἐστιν ἐκ τῶν κατὰ τὸν Δανιήλ, τηλικούτου ἐπηρτημένου αὐτῷ κινδύνου εὐχόμενον τρὶς τῆς ἡμέρας. καὶ ὃ Πέτρος δὲ ἀναβαίνων εἰς τὸ δῶμα τὴν ἕκτην ὥραν προσεύξασθαι, ὅτε καὶ ἑώρα τὸ ἐξ οὐρανοῦ καθιέμενον σκεῦος τέτρασιν ἀρχαῖς καθιέμενον, παρίστησι τὴν μέσην τῶν τριῶν εὐχὴν, τὴν πρὸ αὐτοῦ καὶ παρὰ τοῦ Δαυὶδ λεγομένην· τὸ πρωῒ εἰσακούσῃ τῆς προσευχῆς μου, τὸ πρωῒ παραστήσομαί σοι καὶ ἐπόψομαι· καὶ τῆς τελευταίας δηλουμένης διὰ τοῦ· ἔπαρσις τῶν χειρῶν μου θυσία ἑσπερινή. ἀλλ᾽ οὐδὲ τὸν τῆς νυκτὸς καιρὸν χωρὶς ταύτης τῆς εὐχῆς καθηκόντως διανύσομεν, τοῦ μὲν Δαυὶδ λέγοντος· μεσονύκτιον ἐξεγειρόμην τοῦ ἐξομολογεῖσθαί σοι ἐπὶ τὰ κρίματα τῆς δικαιοσύνης σου· τοῦ δὲ Παύλου, ὡς ἐν ταῖς Πράξεσι τῶν ἀποστόλων εἴρηται, κατὰ τὸ μεσονύκτιον ἅμα τῷ Σίλᾳ ἐν Φιλίπποις προσευχομένου καὶ ὑμνοῦντος τὸν θεόν, ὥστε ἐπακροᾶσθαι αὐτῶν(?) καὶ τοὺς δεσμίους.