תּלמוד אויף משלי 17:28

גַּ֤ם אֱוִ֣יל מַ֭חֲרִישׁ חָכָ֣ם יֵחָשֵׁ֑ב אֹטֵ֖ם שְׂפָתָ֣יו נָבֽוֹן׃

אַפֿילו אַ נאַר אַז ער שװײַגט װערט גערעכנט אַ חכם;דער װאָס מאַכט צו זײַנע ליפּן, אַ פֿאַרשטאַנדיקער.

Jerusalem Talmud Pesachim

Bar Qappara stated: Silence behoves the Sages, and so much more the fools. And also Solomon says135Prov. 17:28., also a silent dolt is considered to be wise, and it is not necessary to say, a silent sage136Since the only uncomplicated case in the Mishnaiot is when nobody says anything. Babli 99a..
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Avot DeRabbi Natan

Wisdom does not produce words, and words do not produce wisdom; only action does. Anyone who talks too much brings about sin, as it says (Proverbs 10:19), “When there is too much talking, there is no lack of sin.” And it says (Proverbs 17:28), “Even a fool, if he keeps silent, is deemed wise.”
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