Be Our Guest

The pasuk says (Bereishis 18:3), “And he [Avraham Avinu] said: ‘My master, if I found favor in your eyes, please pass not away from your servant.’”
Rashi on Shavuos says that the simple explanation of “My master” is that he was addressing the middle of the three guests. It seemed to Avraham Avinu that he was their leader, and if he would stay and consent to being his guest, then the two other guests would stay as well.
However, Chanina ben Achi, Rebbi Yehoshua, and Rebbi Elazar ben Azariah understand the pasuk differently. Avraham Avinu was in middle of talking to Hashem when he saw the three strangers. He asked Hashem to not depart from him while he attended to his guests. The Gemara explains that the statement that “entertaining guests is greater that greeting the Divine Countenance” follows this view.
Avraham Avinu had two choices – continue speaking to Hashem or tend to total strangers. He chose the latter because that is what Hashem wanted him to do. The Chochmas HaMitzpun points out that this illustrates the halacha in Yoreh Deah that if someone is growing spiritually by learning Torah and there is a chessed that cannot be performed by others, he should interrupt his spiritual growth to do the chessed.