After the birth of Isaac, Abraham concluded a treaty with the local Philistine king and opened an inn in Beersheba, where he taught wayfarers about monotheism.
Being a Positive Influence
וַיִּטַּע אֵשֶׁל בִּבְאֵר שָׁבַע וַיִּקְרָא שָׁם בְּשֵׁם ה' אֵל עוֹלָם: (בראשית כא:לג)
[Abraham] planted an orchard [and opened an inn] in Beersheba. There he proclaimed the name of G‑d. Genesis 21:33

Abraham’s inn was the first public institution devoted to the dissemination of the belief in monotheism and to the ethical behavior that follows from this belief. By establishing a public institution that challenged the world’s hallowed tenets, Abraham promoted the awareness of monotheism even among people who never actually visited his inn. As its renown spread, Abraham’s inn wielded increasingly profound and broad influence.

Likewise today, the very existence of synagogues and institutions of Torah study exert great positive influence upon a city simply by the mere virtue of their presence, over and above the intrinsic value of the study and prayer that take place within their walls.1