Rebuke Brings About Peace
A respectful and polite greeting from one person to another can bring peace and reconciliation among mankind (the source is in the beginning of the Tanakh, even to the greeting, as in the proverb of Tu Lo: "The ear that hears the greeting of life - in the company of the wise it hangs").
("And from four things there is no one who can make a man laugh, except with a loud voice: so that his laugher will not be the one who makes him laugh, and his laugher will not be the one who makes him laugh, and his friend will not see him and be ashamed of him, and his heart will not be against him, and the laughers will not be the one who makes him laugh, whose laughter brings peace to the hands of the wise" - Yalkut Shimon Torah Parashat Dvirim Hint)
Translation
Expression (Hebrew)
הַתּוֹכֵחָה מְבִיאָה לִידֵי שָׁלוֹם
Definition (Hebrew)
תּוֹכֵחָה הוֹגֶנֶת וּמְנֻמֶּסֶת הַנֶּאֱמֶרֶת מֵאָדָם לַחֲבֵרוֹ יְכוֹלָה לְהָבִיא שָׁלוֹם וּפִיּוּס בֵּין בְּנֵי הָאָדָם (הַמָּקוֹר בְּפִתְגְּמֵי הַתָּנָ"ךְ בְּעַד הַתּוֹכֵחָה כְּמוֹ בְּמִשְׁלֵי טוּ לֹא:"אֹזֶן שֹׁמַעַת תּוֹכַחַת חַיִּים- בְּקֶרֶב חֲכָמִים תָּלִין").
("וּמִפְּנֵי אַרְבָּעָה דְּבָרִים אֵין מוֹכִיחִים אֶת הָאָדָם אֶלָּא סָמוּךְ לַמִּיתָה: כְּדֵי שֶׁלֹּא יְהֵא מוֹכִיחוֹ וְחוֹזֵר וּמוֹכִיחוֹ, וְשֶׁלֹּא יְהֵא חֲבֵרוֹ רוֹאֵהוּ וּמִתְבַּיֵּשׁ מִמֶּנּוּ, וְשֶׁלֹּא יְהֵא בְּלִבּוֹ עָלָיו, וְשֶׁלֹּא יְהוּ הַמּוֹכִיחִים מִתְוַכְּחִין, שֶׁהַתּוֹכָחָה מְבִיאָה לִידֵי שָׁלוֹם"- יַלְקוּט שִׁמְעוֹנִי תּוֹרָה פָּרָשַׁת דְּבָרִים רֶמֶז)