"We should speak only when circumstances or the glory of God or love for our neighbor requires it.  Apart from these cases it is better to be silent. In silence we find the spirit of recollection and the grace of God which is its source. We learn that to be recollected and interior people we must speak but little, and then say what the Spirit tells us in our heart we ought to say.

Readiness to speak too much is the sign of a distracted heart and mind, and such distraction is already a great evil. 

Sentiments of piety easily vanish in the course of conversation; silence on the contrary preserves and strengthens them. 

You will find few people who repent of having kept silence, but many who regret having said too much.

The wise man speaks only when the right moment comes (Sirach 20:6), that is, when silence would be wrong or unfitting. 

Whenever many words are spoken, sin is not lacking. (Proverbs 10:19) The man who speaks less is always more prudent. 

Constant experience tells us that where there is greater silence, there is greater innocence. Remember the principle that it is always better to remain silent when there is no need to speak.  It is a great art to be able deliberately to speak or remain silent, and men can be quite expert in everything else but ignorant here. Grace gives us better instruction than all the teachings of men. 

The less you speak to creatures, the more God will speak to your heart."

The Imitation of the Blessed Virgin