The Gr"a says that the 613 mitzvos are merely the general commandments, because the specific details of each mitzva are endless. He proves this idea from the fact that many parshios in the Torah contain not even a single one of the 613 mitzvos. If we were not supposed to be gleaning details from these parshios with regard to the performance of mitzvos, for what purpose were they written? Rav Wolbe comments (Shiurei Chumash) that Parshas Vayeira is a case in point of this idea of the Vilna Gaon. Despite the fact that it contains not a single commandment, it contains a veritable "Shulchan Aruch" with regard to the area of chesed. Vayeira commences with recounting Avraham's extraordinary hachnasas orchim.
Despite Avraham's very advanced age and weak state of health, as he recovered from his circumcision, he nevertheless went out searching for guests in the scorching sun. When he finally spotted the G-d-sent angels in the guise of Arabs, he asked Hashem to put their conversation on hold(!) so that he could tend to his guests. He offered his guests merely bread, but then hurried to prepare them a gourmet meal: slaughtering three cows so that he could give each one the best cut of meat. Avraham didn't wait until the entire meal was prepared; as each dish was made he hurried to bring the food to his hungry visitors. He waited over them as they ate, and personally escorted them after they finished their meal.
However, the chesed mentioned in this week's parsha is not limited to Avraham i.e. the host. The Torah tells us that the angels asked Avraham, "Where is your wife Sarah?" to which he answered that she could be found inside the tent. Rashi points out that although the angels knew the whereabouts of Sarah, they asked Avraham so that he would appreciate his wife's modesty. It didn't make a difference that Avraham was nearly one hundred years old and had been married for over seventy years - a wife should always be endeared to her husband. This is chesed that pertains to a guest.
Moreover, the Torah reveals a chesed performed by Hashem Himself. After being informed that she would give birth to a child, Sarah laughed and questioned the possibility of such an event in light of the old age of Avraham. Hashem (the G-d of truth) repeated this conversation to Avraham - with a small change intended to preserve their marital harmony. Instead of relaying that Sarah said, "My husband is old" He stated that Sarah said, "I am old." Chazal derive from Hashem's remark that it is permissible to lie for the sake of making peace. When the intention is one of chesed, an untruth cannot be considered deceit.
Our second encounter with the chesed performed by Avraham comes in the wake of his being informed about the imminent destruction of the cities of Sodom and Amorah. Though the inhabitants were wicked, he was concerned about them and extended himself on their behalf by praying fervently for their survival. They were neither his colleagues nor his friends - he didn't even know them; they needed help and he did everything in his ability to save them.
If we take a minute to study this Shulchan Aruch of chesed, we will find many aspects that we can incorporate into our everyday lives. There is nothing loftier than helping another, there is almost never a situation where it is too difficult to perform chesed, and it is never beneath one's dignity to personally perform the kindness. The beneficiary deserves the very best treatment, without delay and every single person is a potential beneficiary - regardless of his greatness, age or social status. We have much to gain from an in depth study of the parsha - even one that contains none of the 613 commandments!