When the door of steam baths is continually left open, the heat inside rapidly escapes through it; likewise the soul in its desire to say many things, dissipates the remembrance of God through the door  of speech, even though everything it says may be good. .. Ideas of value always shun verbosity, being foreign to confusion and fantasy. Timely silence, then, is precious, for it is nothing less than the mother of the wisest thoughts. – Saint Diadochos of Photiki (c. 486), On Spiritual Knowledge

Apt silence bridles anger.    Ilias the Presbyter (early 12th c.)

If you pile up on one side of the scales all the works demanded by ascetic life, and on the other side-silence, you will find that the latter outweighs the former. Many good counsels have been given us, but if a man embraces silence, to follow them will become superfluous. – Saint Isaac of Syria

I shall indicate to you the most direct and simple method to acquire the habit of silence: …reflect as often as you can on the pernicious results of indiscriminate babbling and on the salutary results of wise silence. When you come to taste the good fruit of silence, you will no longer need lessons about it. – Saint Nikodemos of the Holy Mountain, Unseen Warfare