And he lifted his eyes and saw, and behold, three men were standing beside him, and he saw and he ran toward them from the entrance of the tent, and he prostrated himself to the ground.And he said, “My lords, if only I have found favor in your eyes, please do not pass on from beside your servant. (Genesis 18:2-3)
The Gemara (Shabbat 127a) notes that Abraham seemingly interrupted his conversation with God in order to invite the three men into his tent indicating that the mitzvah of hachnasat orchim – welcoming guests into one’s house, is an even greater mitzvah than receiving the Divine presence. Rabbi Menachem Meiri (d. 1310) notes that in terms of derech eretz – good social behaviour, there is no greater mitzvah (ibid).
Rabbi Moshe Isserlis (d. 1572) contends that in essence the concept of hachnasat orchim was to provide for the impoverished and destitute and to host visitors who have no place to eat or sleep (Orach Chaim 333:1). According to his position, while it is nice to invite friends over, if they could have eaten or slept in their own home it is nothing more than a social gesture. Even so, some authorities do include social gatherings of this sort in the mitzvah of hachnassat orchim as it encourages friendships and communal bonding (Minhag Yisrael Torah 132:7).
The Chofetz Chaim (d. 1933) also details the measures a host should take to ensure that their guest has a pleasant and comfortable experience. For example, one should greet their guest with a happy face and offer them something to eat or drink so that they will not be embarrassed to ask. The host should serve the meal so that guests should feel free to eat and drink to their own content. When the guest wishes to leave, the host should escort them from the house at least 4 amos (cubits) which is approximately 2 metres and give them directions home.
From the kind actions of our forefather Abraham we learn that something as mundane as eating or sleeping can be transformed into a great mitzvah with everlasting merit.