Elder Joseph, ''Such practice is being kept on Mount Athos and in the monastery of Vatopedi as well.'' Elder Joseph the Hesychast used to say that in that way the mind can easier accept its meaning. It helps a monk to keep his attention. Uttering of this prayer reduces or completely removes in quietude: “lips simply move your mind.” Then comes the moment when man can not say the prayer with his lips, since it transforms in a more perfect form – prayer of the heart.
Elder Ephraim of Vatopedi