Volunteering - a Jewish Value?
(א) וַיֵּרָ֤א אֵלָיו֙ יְהוָ֔ה בְּאֵלֹנֵ֖י מַמְרֵ֑א וְה֛וּא יֹשֵׁ֥ב פֶּֽתַח־הָאֹ֖הֶל כְּחֹ֥ם הַיּֽוֹם׃ (ב) וַיִּשָּׂ֤א עֵינָיו֙ וַיַּ֔רְא וְהִנֵּה֙ שְׁלֹשָׁ֣ה אֲנָשִׁ֔ים נִצָּבִ֖ים עָלָ֑יו וַיַּ֗רְא וַיָּ֤רָץ לִקְרָאתָם֙ מִפֶּ֣תַח הָאֹ֔הֶל וַיִּשְׁתַּ֖חוּ אָֽרְצָה׃ (ג) וַיֹּאמַ֑ר אֲדֹנָ֗י אִם־נָ֨א מָצָ֤אתִי חֵן֙ בְּעֵינֶ֔יךָ אַל־נָ֥א תַעֲבֹ֖ר מֵעַ֥ל עַבְדֶּֽךָ׃ (ד) יֻקַּֽח־נָ֣א מְעַט־מַ֔יִם וְרַחֲצ֖וּ רַגְלֵיכֶ֑ם וְהִֽשָּׁעֲנ֖וּ תַּ֥חַת הָעֵֽץ׃ (ה) וְאֶקְחָ֨ה פַת־לֶ֜חֶם וְסַעֲד֤וּ לִבְּכֶם֙ אַחַ֣ר תַּעֲבֹ֔רוּ כִּֽי־עַל־כֵּ֥ן עֲבַרְתֶּ֖ם עַֽל־עַבְדְּכֶ֑ם וַיֹּ֣אמְר֔וּ כֵּ֥ן תַּעֲשֶׂ֖ה כַּאֲשֶׁ֥ר דִּבַּֽרְתָּ׃

The Lord appeared to him [Abraham] by the terebinths of Mamre; he was sitting at the entrance of the tent as the day grew hot. Looking up, he saw three men standing near him. As soon as he saw them, he ran from the entrance of the tent to greet them and, bowing to the ground, he said, "My lords, if it please you, do not go on past your servant. Let a little water be brought; bathe your feet and recline under the tree. And let me fetch a morsel of bread that you may refresh yourselves; then go on - seeing that you have come your servant's way." They replied, "Do as you have said." [JPS translation]