Silence should be kept secretly and in your heart

 “Silence should be kept secretly and in your heart. Make sure that is not obvious to others that you maintain silence. As soon as you have said two or three words, continue immediately inside of you to send prayers for everybody to the Lord. Embrace secretly in your heart, with love, the entire world. All the Church … Make holy your silence by praying so is not sterile and barren.”

(Saint Porphyrius Kafsokalyvitis, Anthology of Advices, p. 281)

http://www.orthodoxpath.org/spiritual-life/silence-should-be-kept-secretly-and-in-your-heart/