“He or silence keeps or speaks in season.”
Source: Seven Against Thebes (467 BC), line 619 (tr. Anna Swanwick)
Original
φιλεῖ δὲ σιγᾶν ἢ λέγειν τὰ καίρια.
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Aeschylus 119
ancient Athenian playwright -525–-456 BCRelated quotes
“Men repent speaking ten times, for once that they repent keeping silence.”
The Dignity of Human Nature (1754)
Context: Men repent speaking ten times, for once that they repent keeping silence.
It is an advantage to have concealed one's opinion; for by that means you may change your judgment of things (which every wise man fmds reason to do) and not be accused of fickleness.

“Keep silence for the most part, and speak only when you must, and then briefly.”

Source: Hilkhot De'ot (Laws Concerning Character Traits), Chapter 2, Section 4, p. 32

“We have medicines to make women speak; we have none to make them keep silence.”
Nous avons des remèdes pour faire parler les femmes; nous n'en avons pas pour les faire taire.
La Comédie de celui qui épousa une femme muette [The Man Who Married a Dumb Wife] (1912), Act II, sc. iv

“Silence at the proper season is wisdom, and better than any speech.”

“My silences he mistook for a lack of wit rather than a lack of any need to speak.”
Source: Assassin's Apprentice

Source: Earthsea Books, A Wizard of Earthsea (1968), Chapter 9

“In the silence of the heart, God speaks.”
If you face God in prayer and silence, God will speak to you. Then you will know that you are nothing.
In The Heart Of The World
Source: Knoansw, In The Heart Of The World – Amazing Book Of Mother Teresa, September 03, 2020 https://knoansw.com/in-the-heart-of-the-world-mother-teresa-quotes/

“Silence is the only language god speaks.”
Source: Dime-Store Alchemy