“With my voice I have cried to the Lord.” I have not, that is, cried with the voice of the body, whose sound is made from the vibration of the air, but with the voice of the heart that is silent for human beings but sounds like an outcry to God. Susanna was heard by this voice. With this voice the Lord has taught to us to pray without sound in the secret places, that is, in the recesses of the heart. Nor would one say that we pray less intensely because of the fact that no word comes out of our mouth. In fact, when we pray silently in our heart, if alien thoughts come to distract the mind of one who prays, we cannot anymore say, “With my voice I have cried to the Lord.” We can rightly say these words only when the soul—without being dragged down with the flesh and having no sexual purposes in mind—alone speaks to the Lord. Then this prayer can be truly called an “outcry” because of the vigor of the tension that the soul experiences. “And he has heard me from his holy mountain.” From the prophet the Lord called a mountain where it is written that the stone that was cut without human hands has grown into the grandeur of a mountain. - "Expositions of the Psalms 3.4"
