In the last section of the third chapter of  Earthen Vessels: The Practice of Personal Prayer According to the Patristic Tradition on “Manners of Praying,” Father Gabriel (Bunge) balances what he had said about praying aloud in the previous section, by pointing to the importance of silence in prayer. The Fathers warn us about vain display in prayer and point out that it is only God who knows what is in our hearts. As Saint John Cassian tells us:

We pray “in secret” when we make our petitions known to God alone in our heart and with a watchful mind, in such a manner that the hostile powers cannot even tell what sort of a petition it is. Therefore one should pray in the most profound silence, not only so as to avoid distracting the brothers around us by our whispering and calling, or disturbing the sentiments of those who are at prayer, but also so that the purpose of our petition might remain hidden from our enemies themselves, who lie in wait for us especially when we pray. In this way, then, we fulfil the commandment: “Guard the doors of your mouth from her who lies in your bosom.” (132)

While the words of the psalms are intended to drive away our adversaries and should be prayed aloud, our intimate conversation with God should remain hidden from them.

Moreover, the words that we use in prayer can sometimes be a distraction to us as well as to our neighbours. Even worse are our own thoughts which can interrupt the immediacy that we desire with God, for true prayer takes place without any mediation between God and the one praying.

Standing in the way of this desired immediacy, nevertheless, are not only our voices and our words but also and above all our “mental images” (νοήματα), insofar as they represent a “mediation” between us and God. This means not only the passionate, sinful “thoughts” but all thoughts whatsoever about created things, or even about God himself, be they ever so sublime, since they hold a person bound to human concerns. In a word, man must “cast aside all mental images” if he wants to “pray in truth”. This “withdrawal” is a step-by-step process corresponding to the ascent in the spiritual life, not a “technique” to be acquired somehow, as one often encounters in many non-Christian methods of “meditation”. Man, to be sure, does his share in this, but he cannot accomplish this “transcendence” by his own power, because the destination, God, is a “Person” who inclines himself to man with absolute freedom. (133-134)

If the grace of entering this “place of prayer” is given then it is fitting that one’s prayer becomes adapted to it. In the words of Diadochos of Photike:

When the soul finds itself amidst the fullness of its natural fruits, then it recites the psalmody with an even stronger voice and desires, more than anything else, to pray aloud. When, however, the Holy Spirit works within it, the it recites the psalms very gently and lovingly and prays in the heart alone.

The first state is followed by a joy that is bound up with mental imagery; the second by spiritual tears and thereafter a certain joy in the heart that loves silence. For being mindful [of God], which maintains its warmth through the moderation of the voice, enables the heart to bring forth tearful, very gentle thoughts. (135)

Father Gabriel points out that

The masters of the spiritual life expressly warn against disturbing this “visitation of the Holy Spirit” by stubbornly clinging to one’s own activity or to any self-imposed “rule.” At this moment the only valid law is that of “the freedom of the children of God”, as the East-Syrian mystic Joseph Hazzaya teaches.

Close the doors of your cell, enter the inner room, and sit down in darkness and seclusion in a place where you do not even hear the song of a bird. Then when the hour for the Divine Office comes, beware, do not stand up, lest you be like a child that in its ignorance exchanges a talent of gold for a fig that sweetens its gums for an instant. But you, like a wise merchant, once you have discovered the “pearl of great price”, do not exchange this for contemptible things that you find before you at all times, lest you end as did that people which went forth from Egypt and which despised the food of the spiritual manna and craved the loathsome food of the Egyptians. (135-136)