By Rabbi Joshua (transiently known as The Hoffer) Hoffman [z"l]
In the beginning of this week's parsha we are told of Avraham's prodigious efforts in caring for the needs of three wayfarers who came by his tent. The rabbis tell us that since Avraham was recuperating from his bris milah, God did not want to trouble him with guests and, therefore, made the weather intensely hot, so that no one would travel. However, because Avraham was so keen on extending hospitality to guests, and was pained by the lack of passersby, God sent three angels in the guise of humans in order to provide Avraham with an opportunity to invite guests into his tent. As soon as Avraham saw the travelers he ran to provide them with what they needed. The Talmud (Bava Metziah, 86b) notes that as a reward for whatever Avraham did for these guests by himself, God provided a similar provision for his descendants in the wilderness, and as a reward for whatever Avraham did for them through someone else, his descendants were also rewarded through a shaliach, meaning a messenger, or an intermediary. Thus, for example, since Avraham prepared the cattle for the meal himself, the Jewish people in the wilderness received the quail directly from heaven. However, since Avraham provided water through a messenger, the Jews in the wilderness received water through Moshe hitting a rock. Why was it so important for Avraham to provide for these guests by himself?
Rabbi Moshe Tzvi Neriah, in his Ner LaMaor, explains that the initial provisions for guests should, in general, be taken care of by the man of the house, because women are very punctilious in serving guests, making sure that the table is set properly, that there are napkins on the table, and so forth. The guests, however, may be very hungry, and they need to be taken care of as soon as possible, without any time being expended on the niceties of the service being provided. Therefore, Avraham needed to act quickly, in order to make sure that his visitors would not go hungry waiting for the table to be set. Interestingly, the Yalkut Reuveni cites a kabalistic source which says that the reason Sarah merited giving birth to Yitzchak is that she accommodated Avraham in his efforts to care for these guests. According to Rav Neriah, this source is understandable, because Avraham tended to their needs differently than a woman usually would have done.
I would like to suggest a different explanation of why it was so important for Avraham himself to tend to his guests, based on what we know of who they actually were. As we noted at the outset, the three wayfarers who came to Avraham were angels in the guise of men. The Maharal, in his commentary to Rashi, Gur Aryeh, points out that Avraham was used to seeing angels, but, in this case, God arranged that he not discern the true nature of his visitors, so that he would be able to perform what, to his mind, was the regular mitzvah of hachnasas orchim, or tending to guests. The Torah tells us that Avraham had the guests wash their feet before entering his tent, and the midrash, cited by Rashi, says that this was because Arab travelers were wont to worship the dust of their feet as idols. The Maharal explains that they did so because Arab merchants were constantly on the move, and therefore worshiped the forces that they thought controlled the roads, in order to ensure that they would complete their journeys safely and successfully. Based on this observation, we can understand why it was so important for Avraham to tend to these travelers by himself, as much as possible.
Rabbi Yehudah Shaviv, in his work Mi Sinai Ba, cites a Midrash (Bereishis Rabbah, 39:9) which notes, in effect, that Avraham began his series of tests with God's command to leave his homeland, which begins with the words' lech lecha' - go for yourself - and ended the series with God's command to bring his son to the altar, which also begins with the words ' lech lecha.' These bookends, says Rabbi Shaviv, denote Avraham's constant movement, and, on a larger scale, his constant process of growth and self-improvement. Perhaps, then when Avraham saw these Arab travelers, and realized that they worshipped the powers that they thought controlled the roads, he felt that, in essence, they had the ability, as travelers, to learn the importance of constant growth and self-improvement, as reflected in their constant travelers, but place it in the context of a relationship with the true God, creator of the universe. Avraham tried to do this by offering himself as an example. Even though he was an elderly man and had just undergone the painful process of circumcision, he leaped into action when he saw these men, and tended to their needs largely by himself. In this way, he tried to demonstrate that a person has the capacity to constantly grow, and need not rely on some outside force to manage his life. In this way, Avraham tried to assist his guests not only in terms of their physical needs, but in terms of their spiritual needs, as well.