Let us therefore, brethren beloved, pray as God our Teacher has taught us. It is a loving and friendly prayer to beseech God with His own word, to come up to His ears in the prayer of Christ. Let the Father acknowledge the words of His Son when we make our prayer, and let Him also who dwells within in our breast Himself dwell in our voice. And since we have Him as an Advocate with the Father for our sins, let us, when as sinners we petition on behalf of our sins, put forward the words of our Advocate. For since He says, that “whatsoever we shall ask of the Father in His name, He will give us,”how much more effectually do we obtain what we ask in Christ’s name, if we ask for it in His own prayer!
But let our speech and petition when we pray be under discipline, observing quietness and modesty. Let us consider that we are standing in God’s sight. We must please the divine eyes both with the habit of body and with the measure of voice. For as it is characteristic of a shameless man to be noisy with his cries, so, on the other hand, it is fitting to the modest man to pray with moderated petitions. Moreover, in His teaching the Lord has bidden us to pray in secret””in hidden and remote places, in our very bed-chambers””which is best suited to faith, that we may know that God is everywhere present, and hears and sees all, and in the plenitude of His majesty penetrates even into hidden and secret places, as it is written, “I am a God at hand, and not a God afar off. If a man shall hide himself in secret places, shall I not then see him? Do not I fill heaven and earth?”And again: “The eyes of the Lord are in every place, beholding the evil and the good.”And when we meet together with the brethren in one place, and celebrate divine sacrifices with God’s priest, we ought to be mindful of modesty and discipline””not to throw abroad our prayers indiscriminately, with unsubdued voices, nor to cast to God with tumultuous wordiness a petition that ought to be commended to God by modesty; for God is the hearer, not of the voice, but of the heart. Nor need He be clamorously reminded, since He sees men’s thoughts, as the Lord proves to us when He says, “Why think ye evil in your hearts?” And in another place: “And all the churches shall know that I am He that searcheth the hearts and reins.”
And this Hannah in the first book of Kings, who was a type of the Church, maintains and observes, in that she prayed to God not with clamorous petition, but silently and modestly, within the very recesses of her heart. She spoke with hidden prayer, but with manifest faith. She spoke not with her voice, but with her heart, because she knew that thus God hears; and she effectually obtained what she sought, because she asked it with belief. Divine Scripture asserts this, when it says, “She spake in her heart, and her lips moved, and her voice was not heard; and God did hear her.”We read also in the Psalms, “Speak in your hearts, and in your beds, and be ye pierced.”The Holy Spirit, moreover, suggests these same things by Jeremiah, and teaches, saying, “But in the heart ought God to be adored by thee.”
–From his Treatise On the Lord’s Prayer