This section is named הר המוריה – the significance of Mount Moriah.

The paragraph commencing with "G–d appeared to him," until the angels had eaten, describes the commandment of being hospitable to guests, though it is not numbered as one of the 613 commandments. It is a subsection of the general positive commandment והלכת בדרכיו, "you shall walk in His ways."

This is the way the סמ"ג describes the commandment as number seven in his list of positive commandments. "One must walk in His good straightforward paths, seeing that the Torah says והלכת בדרכיו, as well as אחרי ה' אלוקיכם תלכו (Deut 13,5), which is interpreted in the Talmud Sotah 14a as a reference to G–d's virtues. Just as G–d provides clothing for the naked, since the Torah says: 'G–d made leather aprons for Adam and his wife and He clothed them,' G–d also visits the sick, as we know from the beginning of this פרשה. G–d comforts the mourners as we know from Genesis 25,11: 'After the death of Abraham G–d blessed Isaac.' G–d also buries the dead, as we know from Deut. 34,6: 'He buried him (Moses) in the valley in the land of Moab.' This is the way I explained the contents of this paragraph to the scholars of Spain. You should know the G–d of your fathers, and serve Him, for just as He is gracious and merciful, so you should be gracious and merciful. Just as He performs acts of kindness, justice and charity on earth, so should you. You have two examples. In Jeremiah 22,15 it is reported of King Josiah that 'he ate, drank and performed justice and righteousness, whereupon all was well with him. Then he judged the poor and the needy, and all was well with him. That is truly heeding Me, says the Lord.' We have another verse in Jeremiah 9,22: 'Thus said the Lord: Let not the wise man glory in his wisdom; let not the strong man glory in his strength…but only in this should one glory; in his earnest devotion to Me, For I the Lord act with kindness, justice and equity in the world; for in these I delight, says the Lord." Thus far the סמ"ג.

It is obvious to me that the מצוה of being hospitable to guests, (which is certainly included in the overall commandment to follow in G–d's footsteps), represents an additional virtue. The Torah has singled out this story of Abraham personally performing chores to entertain these strangers. It also alludes to the reward accruing to him, i.e. that everything he did personally for these guests, G–d later on personally did for Abraham's descendants, whereas whatever Abraham had designated to be done by someone else, G–d also performed for the Jewish people only by means of one of His agents. You should not think that all we talk about here is merely a part of a virtue. Whoever performs such an act such as Abraham's, performs the positive commandment of emulating G–d, and he will receive the reward due to someone who has performed a מצוה which has been specifically commanded. G–d performs acts of hospitality at all times, at every moment. Were He to desist from doing so for even a single moment the world would be lost. All creatures are His guests, we are all like strangers vis-a-vis G–d, and just as strangers we need a place to sleep. G–d enables us to survive. If He were to withdraw life-support for even a moment, we would all perish.

This is what the Talmud Shabbat 127 has in mind when it states that the entertaining of guests is an even greater accomplishment than the welcoming of G–d's Presence since the Torah reports that Abraham asked G–d to wait a few moments: אל נא תעבור אד-ני, אם נא מצאתי חן בעינך מעל עבדך, while he would attend to the guests who had arrived suddenly (18,3).