I remember years ago in Korea in the Peace Corps, how I felt the first time I partook of the daily culture of "just sitting" together with friends in informal tearooms in Seoul, without saying a word; at first I felt quite nervous and bored, but when I was able to relax my mind and just be, it was a refreshing communion... each moment's meeting of a person or even a flower is precious and fleeting, it is to be savored completely, perhaps best in silence.
Fasting from words, fasting from a volume of speech, being willing to humbly accept the yoke of silence and quietude deprives the tongue of the mastery of our hearts and minds. The tongue is a very useful tool for the art of love and for the art of prayer, but it is also the means by which we afflict others and even our own selves so often. So it must be called into holy obedience.