Why does it say: he prayed with himself? Why not aloud? Because God listens more carefully to what his heart says than his lips. What a man thinks and feels as he prays to God is more important to God than the words his tongue forms. The tongue is capable of delusion, but the heart does not delude: it shows a man as he is – black or white.
+ St. Nikolai Velimirovich, Sunday of the Pharisee and the Publican: “The Gospel on True and False Prayer,” Homilies: Commentary on the Gospel Readings for Great Feasts and Sundays Throughout the Year, Volume I