(א) וַיֵּרָ֤א אֵלָיו֙ ה' 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 אדושם 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׃ (ו) וַיְמַהֵ֧ר אַבְרָהָ֛ם הָאֹ֖הֱלָה אֶל־שָׂרָ֑ה וַיֹּ֗אמֶר מַהֲרִ֞י שְׁלֹ֤שׁ סְאִים֙ קֶ֣מַח סֹ֔לֶת ל֖וּשִׁי וַעֲשִׂ֥י עֻגֽוֹת׃ (ז) וְאֶל־הַבָּקָ֖ר רָ֣ץ אַבְרָהָ֑ם וַיִּקַּ֨ח בֶּן־בָּקָ֜ר רַ֤ךְ וָטוֹב֙ וַיִּתֵּ֣ן אֶל־הַנַּ֔עַר וַיְמַהֵ֖ר לַעֲשׂ֥וֹת אֹתֽוֹ׃ (ח) וַיִּקַּ֨ח חֶמְאָ֜ה וְחָלָ֗ב וּבֶן־הַבָּקָר֙ אֲשֶׁ֣ר עָשָׂ֔ה וַיִּתֵּ֖ן לִפְנֵיהֶ֑ם וְהֽוּא־עֹמֵ֧ד עֲלֵיהֶ֛ם תַּ֥חַת הָעֵ֖ץ וַיֹּאכֵֽלוּ׃
(1) G-d appeared to him by the terebinths of Mamre; he was sitting at the entrance of the tent as the day grew hot. (2) 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, (3) he said, “My lords, if it please you, do not go on past your servant. (4) Let a little water be brought; bathe your feet and recline under the tree. (5) 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.” (6) Abraham hastened into the tent to Sarah, and said, “Quick, three seahs of choice flour! Knead and make cakes!” (7) Then Abraham ran to the herd, took a calf, tender and choice, and gave it to a servant-boy, who hastened to prepare it. (8) He took curds and milk and the calf that had been prepared and set these before them; and he waited on them under the tree as they ate.
Avot D'Rabbi Natan 7:17a
Let your house be open; let the poor be members of your household. Let a person’s house be open to the north and to the south and to the east and to the west, even as Abraham’s house was, for Abraham made four doors to his house, that the poor might not be troubled to go round the house, but that each would find they faced a door as they approached . . .
אמר רב יהודה אמר רב גדולה הכנסת אורחין מהקבלת פני שכינה דכתיב ויאמר (ה׳) אם נא מצאתי חן בעיניך אל נא תעבר וגו׳... אמר רב יהודה בר שילא אמר רבי אסי אמר רבי יוחנן ששה דברים אדם אוכל פירותיהן בעולם הזה והקרן קיימת לו לעולם הבא ואלו הן הכנסת אורחין וביקור חולים ועיון תפלה והשכמת בית המדרש והמגדל בניו לתלמוד תורה והדן את חברו לכף זכות
Rav Yehuda said that Rav said on a related note: Hospitality toward guests is greater than receiving the Divine Presence, as when Abraham invited his guests it is written: “And he said: Lord, if now I have found favor in Your sight, please pass not from Your servant” (Genesis 18:3). Abraham requested that God, the Divine Presence, wait for him while he tended to his guests appropriately. ... Rav Yehuda bar Sheila said that Rabbi Asi said that Rabbi Yoḥanan said: There are six matters a person enjoys the profits of in this world, and nevertheless the principal exists for him for the World-to-Come, and they are: Hospitality toward guests, and visiting the sick, and consideration during prayer, and rising early to the study hall, and one who raises his sons to engage in Torah study, and one who judges another favorably, giving him the benefit of the doubt.
The reward for escorting guests is greater than any other. It is a practice introduced by our father Abraham, a way of kindness which was habitual with him. He served food and drink to wayfarers and escorted them. Hospitality to wayfarers is greater than welcoming the Divine Presence, as it is written: "He saw three men … he ran to meet them" (Genesis 18:2). Escorting them is even greater than receiving them. The sages have declared: "Anyone who does not escort his guests it is as if he sheds blood" (Sotah 46b).