Silence and Speech

(ג) וַיֹּ֨אמֶר מֹשֶׁ֜ה אֶֽל־אַהֲרֹ֗ן הוּא֩ אֲשֶׁר־דִּבֶּ֨ר יי ׀ לֵאמֹר֙ בִּקְרֹבַ֣י אֶקָּדֵ֔שׁ וְעַל־פְּנֵ֥י כָל־הָעָ֖ם אֶכָּבֵ֑ד וַיִּדֹּ֖ם אַהֲרֹֽן׃

Leviticus 10:3

(3) Then Moses said to Aaron, “This is what the LORD meant when He said: Through those near to Me I show Myself holy, And gain glory before all the people.” And Aaron was silent.

משנה אבות א׳:ה׳

(ה) יוֹסֵי בֶן יוֹחָנָן אִישׁ יְרוּשָׁלַיִם אוֹמֵר, יְהִי בֵיתְךָ פָתוּחַ לִרְוָחָה, וְיִהְיוּ עֲנִיִּים בְּנֵי בֵיתֶךָ, וְאַל תַּרְבֶּה שִׂיחָה עִם הָאִשָּׁה. בְּאִשְׁתּוֹ אָמְרוּ, קַל וָחֹמֶר בְּאֵשֶׁת חֲבֵרוֹ. מִכָּאן אָמְרוּ חֲכָמִים, כָּל זְמַן שֶׁאָדָם מַרְבֶּה שִׂיחָה עִם הָאִשָּׁה, גּוֹרֵם רָעָה לְעַצְמוֹ, וּבוֹטֵל מִדִּבְרֵי תוֹרָה, וְסוֹפוֹ יוֹרֵשׁ גֵּיהִנֹּם:

Pirkei Avot 1:5

(5) Yose ben Yochanan, man of Jerusalem, says, "May your home be open wide, may the poor be members of your household and do not increase conversation with the woman." They so stated with his wife; all the more so with the wife of his friend. From this, the sages said, "Any time that a man increases conversation with the woman, he causes evil to himself and neglects the words of Torah; and, in his end, he inherits Geihinam."

יבמות ס״ה ב:ו׳

ואמר רבי אילעא משום ר' אלעזר בר' שמעון כשם שמצוה על אדם לומר דבר הנשמע כך מצוה על אדם שלא לומר דבר שאינו נשמע רבי אבא אומר חובה שנאמר (משלי ט, ח) אל תוכח לץ פן ישנאך הוכח לחכם ויאהבך

Yevamot 65b:6

The Gemara cites other statements made by Rabbi Ile’a in the name of Rabbi Elazar, son of Rabbi Shimon. And Rabbi Ile’a said in the name of Rabbi Elazar, son of Rabbi Shimon: Just as it is a mitzva for a person to say that which will be heeded, so is it a mitzva for a person not to say that which will not be heeded. One should not rebuke those who will be unreceptive to his message. Rabbi Abba says: It is obligatory for him to refrain from speaking, as it is stated: “Do not reprove a scorner lest he hate you; reprove a wise man and he will love you” (Proverbs 9:8).

Even when you speak with others about the wisdom of the Torah, silence is still preferable. Silent contemplation offers greater possibilities for connection with the Divine than does discussion or speech.
-- R. Dov Baer of Mezrich, trans. R. Or Rose & R. Ebn Leader

משנה אבות ג׳:י״ג

(יג) רַבִּי עֲקִיבָא אוֹמֵר, שְׂחוֹק וְקַלּוּת רֹאשׁ, מַרְגִּילִין לְעֶרְוָה. מָסֹרֶת, סְיָג לַתּוֹרָה. מַעַשְׂרוֹת, סְיָג לָעשֶׁר. נְדָרִים, סְיָג לַפְּרִישׁוּת. סְיָג לַחָכְמָה, שְׁתִיקָה:

Pirkei Avot 3:13

(13) Rabbi Akiva says: Joking and lightheartedness acclimate toward promiscuity. Tradition is a safeguarding fence around Torah. Tithes are a safeguarding fence around wealth. Vows are a safeguarding fence around abstinence. A safeguarding fence around wisdom is silence.

מלכים א י״ט:י״ב

(יב) וְאַחַ֤ר הָרַ֙עַשׁ֙ אֵ֔שׁ לֹ֥א בָאֵ֖שׁ יי וְאַחַ֣ר הָאֵ֔שׁ ק֖וֹל דְּמָמָ֥ה דַקָּֽה׃

I Kings 19:12

(12) After the earthquake—fire; but the LORD was not in the fire. And after the fire—a soft murmuring sound.

Souls on Fire (Wiesel, trans. Wiesel), chapter 1
[The Baal Shem Tov] wanted to know everything, understand everything. Each of his disciples was convinced that the Master saw no-one but him. One day, says legend, his disciples understood that in his eyes they were all equal -- and "they remained silent a long time."