“P lease let a little water be taken and bathe your feet.” (Bereishis 18:4)
Rashi says that Avraham thought his visitors were Arabs who bowed to the dust on their feet and he didn’t want to bring avodah zarah into his house.
Hashem specifically sent guests who looked like Arabs to teach us that the mitzvah of hachnassas orchim is enhanced when the host opens his home to anyone in need even a simple person. Someone who insists on hosting only important guests has not fulfilled this hiddur mitzvah because he himself benefits from honoring illustrious guests. (Rav Moshe Shternbach Taam V’Daas)
Eons ago I used to have guests. It was fun to fill up my Shabbos table with food friends family and philosophy. But fast-forward a few decades and our open-door policy has slammed shut. It’s hard to be gracious when defusing an intense under-the-table kicking competition and the only philosophy discussed is “Why me?”