1) One should seek out the opportunity to perform the mitzvah - Among the positive commandments in the Torah, there are those which one must initiate, and those which one need fulfill only when the opportunity presents itself. It would seem that hachnasat orchim would fall into the second category. According to Rashi (Bereshit 18:1), however, it would seem that Avraham was driven to go out of his way to perform this mitzvah:

רש"י: כחום היום - הוציא הקב"ה חמה מנרתיקה שלא להטריחו באורחים, ולפי שראהו מצטער שלא היו אורחים באים, הביא המלאכים עליו בדמות אנשים.

Rashi: In the heat of the day - The Holy One Blessed Be He brought the sun out of its sheath so that he (Avraham) would not be bothered by guests. When He saw that he was distressed that no guests, he brought the angels to him in the form of men.

Certainly, his recovery from the circumcision could have served as a rationale for Avraham to be satisfied with the fact that no visitors happened to stop by his tent on that particular day. However, God’s attempt to protect Avraham from exerting himself only led to his unhappiness at not being able to fulfill the mitzvah. Rashi’s explanation is based on several irregularities in the text:

a) In its description of events, the Torah does not generally give a weather report. It would seem, therefore, that the heat of the day is in some way relevant to the events in this particular story. Thus, Rashi quotes the Gemara that explains the heat as an unusual occurrence designed to protect Avraham.

b) The unusual nature of the heat is also reflected in the use of the expression “כחום היום” (lit. “as the heat of the day”) rather than “בחום היום” which would be the normal way to say “in the heat of the day”. This indicates that the heat was artificially created.

c) The fact that the Torah refers to the angels as “men” relates only to Avraham’s perception of them during this short period of time. Later, their true identities and mission become clear to Avraham. Rashi’s explanation explains why they initially appeared in the form of men.

2) Sensitivity to the Feelings and Needs of the Recipient - Ralbag derives a number of lessons from Avraham’s example of hachnasat orchim. Two in particular relate to the sensitivity that one must show in the performance of mitzvot between man and man for the feelings and needs of the recipient:

a) “The Third Lesson” -

התועלת השלישי במדות: והוא שראוי למי שייטב לאנשים שיראה להם שהוא
מקבל טובה מהם, במה שיקבלו ממנו, לא שיתפאר על הטוב שייטיב להם…
ולזה תמצא שאברהם הראה לאלו האנשים שהם נותנים לו מתנה בבואם אל
ביתו...

The third benefit relating to character: It is appropriate for one who is doing an act of kindness for others to make it appear that he is receiving a favor from them in that they accept something from him, and not to glorify himself over the kindness that he is doing for them…And you will find in this regard that Avraham made it appear to these men that they were giving him a present by coming to his house…

Ralbag derives this principle from the language that Avraham utilizes in inviting the angels to stop at his tent:

"ויאמר אדני אם נא מצאתי חן בעיניך אל נא תעבור מעל עבדיך." (בראשית יח:ג)

“And he said: ‘My lords, if I have found favor in your sight, pass not, I pray thee, from your servant.” (Bereshit 18:3) This formulation makes the guests feel that their visit is for Avraham’s benefit rather than theirs. This concept is found, as well, in Rashi’s commentary on verse 18:5:

כי על כן עברתם על עבדכם - כי הדבר הזה אני מבקש מכם מאחר שעברתם
עלי לכבודי.

Since you have come to your servant - This I request of you since you have come here as an honor to me.

b) “The Fourth Lesson” -

התועלת הרביעי במדות: והוא שראוי למיטב שישתדל שלא יכבד ענין הטבתו למקבל הטבתו, אבל ישלים הטבתו ביותר שלם ונאות שאפשר למקבל הטובה ממנו.

The fourth benefit relating to character: It is appropriate for one who is doing an act of kindness for others that his kindness should not cause difficulty for the recipient. Rather, his kindness should be complete and as pleasant as possible for the recipient.

Avraham perceived that the passers-by were in a hurry to continue on their way. He, therefore, he hurried to prepare food for them and served it in stages in order to minimize the interruption to their travel.

Ralbag learns from Avraham’s behavior that in performing mitzvot between man and man, it is important to realize that even acts of kindness can cause the recipient inconvenience or discomfort. Thus, the manner in which one performs acts of kindness requires a heightened sensitivity to this issue.

3) Say Little and Do Much: Avot d’Rabbi Natan (13:3) states:

אמור מעט ועשה הרבה: מניין שהצדיקים אומרים מעט ועושין הרבה? שכן מצינו באברהם אבינו שאמר למלאכים: פת אתם סועדים עמי היום שנאמר: "ואקחה פת לחם וסעדו לבכם", אבל באחרונה ראה מה עשה אברהם למלאכי השרת שהלך ועשה להם שלשה שוורים ותשע סאין של םולת.

Say little and do much: From where do we know that righteous people say little and do much? We find that our father Avraham said to the angels: “You will eat bread with me today” as it says: And I will get a piece a loaf of bread so you can eat to your hearts content.” But in the end, look what Avraham did for the angels – he went and prepared three oxen and nine measures of the finest flour.

The derivation of this concept is based on the fact that Avraham offered his guests only some bread, but served them a feast that included meat and fine baked goods. This behavior is contrasted by the Midrash with that of Ephron, who at first offered a burial plot to Avraham as a gift, but later sold it to him for a high price. Ralbag adds that offering less makes it more comfortable for the recipient to accept an offer of hospitality or kindness. It also reduces the possibility that one will become haughty as a result of his performance of acts of kindness.

Mitzvot Between Man and Man vs. Communion With God

The Gemara (Shabbat 127a) derives the extreme importance of hachnasat orchim from the fact that that Avraham apparently withdrew from an encounter with God in order to greet the strangers who were passing by his tent:

אמר ר' יהודה אמר רב: גדולה הכנסת אורחים מהקבלת פני השכינה דכתיב: (בראשית יח:ג) "ויאמר אדוני אם נא מצאתי חן בעיניך אל נא תעבור…"

And Rav Yehuda said in the name of Rav: The mitvah of welcoming guests is greater than welcoming the Divine Presence (שכינה), as it is written Bereshit 18:3): “And he said, my Lord, if I have found favor in your eyes, do not pass your servant by…”

This Gemara is based on an alternative explanation of the Biblical verse found in Rashi. The term “adonai” in the verse is usually translated “my lords”, indicating that Avraham was addressing the angels. In the alternative explanation, the term refers to God:

רש"י:ויאמר אדני: … ד"א קודש הוא, והיה אומר להקב"ה להמתין לו עד שירוץ ויכניס את האורחים.

Rashi: And he said my lords: Another explanation is that the word is sacred (referring to God), and that he was requesting that the Holy One Blessed Be He wait for him while he ran to welcome the guests.

According to the Gemara, in order to fulfill the mitzvah of hachnasat orchim, Avraham chose to interrupt an intimate encounter with God. This formulation views Avraham’s decision as a clear and correct prioritization of values. The Netziv, however, in his commentary on Devarim 28:9, brings out the tension between communion with God (“devekut”) and the performance of ethical commandments:

"יקימך ה' לו לעם קדוש כאשר נשבע לך כי תשמר את מצות ה' אלקיך והלכת בדרכיו."

העמק דבר (הנצי"ב): כי תשמור: באופן שמי שרוצה להתנהג בקדושה ודביקות לא יחפוץ להיבדל ממעשה המצוות שלפעמים הם מסירים דביקות….ויותר נראה שהאי "כי תשמור" אינו תנאי, שהרי כבר כתוב התנאי בראש הפרשה, אלא הוא ברכה דתשיג מדת הקדושה והדביקות בה' אפילו בשעה שתשמור את מצוות ה'… ויש כמה מצוות מעשיות שאי אפשר לעשותם בשעת דביקות ומכל שכן "והלכת בדרכיו" שהוא עסקי בני אדם, ועי"כ יסיח דעתו בשעת מעשה הקדושה ודביקות. מכל מקום "יקימך ה' לעם קדוש" ומיד אחר המעשה תשיג הדביקות והקדושה כמו שהיה תחילה – והוא סייעתא דשמיא וברכה, דכתיב באברהם אבינו בעת ביאת האורחים והוא היה מתקדם ודבק באלוקיו.