Avot3: 2
רַבִּי חֲנִינָא סְגַן הַכֹּהֲנִים אוֹמֵר: הֱוֵי מִתְפַּלֵּל בִּשְׁלוֹמָהּ שֶׁל מַלְכוּת, שֶׁאִלְמָלֵא מוֹרָאָהּ — אִישׁ אֶת רֵעֵהוּ חַיִּים בְּלָעוֹ.  רַבִּי חֲנַנְיָא בֶּן תְּרַדְיוֹן אוֹמֵר: שְׁנַיִם שֶׁיּוֹשְׁבִין, וְאֵין בֵּינֵיהֶן דִּבְרֵי תוֹרָה — הֲרֵי זֶה מוֹשַׁב לֵצִים, שֶׁנֶּאֱמַר: ”וּבְמוֹשַׁב לֵצִים לֹא יָשָׁב”. אֲבָל שְׁנַיִם שֶׁיּוֹשְׁבִין, וְיֵשׁ בֵּינֵיהֶם דִּבְרֵי תוֹרָה — שְׁכִינָה שְׁרוּיָה בֵינֵיהֶם, שֶׁנֶּאֱמַר: ”אָז נִדְבְּרוּ יִרְאֵי ה' אִישׁ אֶל־רֵעֵהוּ, וַיַּקְשֵׁב ה' וַיִּשְׁמָע, וַיִּכָּתֵב סֵפֶר זִכָּרוֹן לְפָנָיו לְיִרְאֵי ה' וּלְחשְׁבֵי שְׁמוֹ”. אֵין לִי אֶלָּא שְׁנַיִם, מִנַּיִן שֶׁאֲפִלּוּ אֶחָד שֶׁיּוֹשֵׁב וְעוֹסֵק בַּתּוֹרָה, שֶׁהַקָּדוֹשׁ בָּרוּךְ הוּא קוֹבֵעַ לוֹ שָׂכָר? שֶׁנֶּאֱמַר: ”יֵשֵׁב בָּדָד וְיִדֹּם כִּי נָטַל עָלָיו”.
Rabbi Chanina, the Deputy Kohen [Gadol], says: Pray for the welfare of the government, because if people did not fear it, a person would swallow his fellow alive.  Rabbi Chanania ben Tradyon says: [When] two people are sitting [together] and there are no words of Torah between them, this is a session of scorners, as it is stated: In the session of scorners he did not sit. But two who are sitting [together] and there are words of Torah between them, the Divine Presence dwells between them, as it is stated: Then those who fear Hashem spoke to each other, and Hashem listened and heard, and a book of remembrance was written before Him for those who fear Hashem and give thought to His Name. I only know two. From where [do we know] that even one person who sits and occupies himself with Torah, that the Holy One, Blessed is He, determines a reward for him? as it is stated: Let one sit in solitude and whisper, for he has taken [a reward] for it.
Avot3: 3
רַבִּי שִׁמְעוֹן אוֹמֵר: שְׁלשָׁה שֶׁאָכְלוּ עַל שֻׁלְחָן אֶחָד, וְלֹא אָמְרוּ עָלָיו דִּבְרֵי תוֹרָה — כְּאִלּוּ אָכְלוּ מִזִּבְחֵי מֵתִים, שֶׁנֶּאֱמַר: ”כִּי כָּל־שֻׁלְחָנוֹת מָלְאוּ קִיא צֹאָה בְּלִי מָקוֹם”. אֲבָל שְׁלשָׁה שֶׁאָכְלוּ עַל שֻׁלְחָן אֶחָד, וְאָמְרוּ עָלָיו דִּבְרֵי תוֹרָה — כְּאִלּוּ אָכְלוּ מִשֻּׁלְחָנוֹ שֶׁל מָקוֹם בָּרוּךְ הוּא, שֶׁנֶּאֱמַר: ”וַיְדַבֵּר אֵלַי, זֶה הַשֻּׁלְחָן אֲשֶׁר לִפְנֵי ה' ”.
Rabbi Shimon says: [If] three people ate at the same table and did not speak words of Torah upon it, it is as if they ate from offerings of the dead, as it is stated: For all tables are full of vomit [and] filth, without the Omnipresent. But three who ate at the same table and spoke words of Torah upon it, it is as if they ate from the table of the Omnipresent, Blessed is He, as it is stated: And [the angel] said to me, “This is the table that is before Hashem.”