The Potential Impact of a Mitzvah

The last train has already left, and a student who has just been told to leave the yeshiva that night has nowhere to sleep. The Chofetz Chaim's reaction changes everything. In Vayera, Avraham sits at his tent in pain three days after his bris, worried that no guests are coming. Why would he be upset that nobody needs help? And what good is it that Hashem sends angels dressed as travelers, when angels are not real guests? Rav Shlomo Heiman answers both by looking at what Avraham thought his day was for.