We generally understand the “covenant of Avraham Avinu” as referring to circumcision, and accordingly the father recites at theberit milah, “…Who has commanded us to bring him [the newborn] into the covenant of Avraham Avinu.” But another rabbinical source teaches that there is another covenant. We are told, in Massekhet Kebubot 8b: “He said to him: ‘Arise, say something in response to those who comfort the mourners’. He started to speak, saying: ‘Our brethren are people who perform kindness – descendants of people who perform kindness, maintaining the covenant of Avraham Avinu.” From here we learn that an additional covenant was made with Avraham: “The covenant of kindness of Avraham, our father.”
These two covenants symbolize two aspects of Avraham’s personality: first and foremost, there is his obedience of G-d’s word by accepting the yoke of the commandments, as expressed in circumcision – “whereby,” teaches the Vilna Gaon, “a person is introduced to the other 612 commandments”.
But the other aspect of Avraham is his outgoing love and concern for all that know no bounds, finding expression in his trait of loving kindness. Avraham’s startling and innovative message – that “showing hospitality is greater a deed than accepting the Divine presence” – teaches us that there is another way to serve G-d: through the imitation and dissemination of His ways. What is going on when the three “men” arrive at Avraham’s home? The Creator Himself has come to visit Avraham on the third day after his circumcision, to show concern for his welfare. And while the Holy One is in the midst of talking to Avraham, Avraham notices that three unfamiliar men are wandering at a distance from his tent. He immediately jumps up – without so much as excusing himself before G-d – and runs towards them. An onlooker would be quite astonished at Avraham’s behavior: “The King is talking to you, and not only do you not pay proper attention; you halt the conversation and run off to invite some strangers while the King of Kings is present in your tent?!”
Not only does G-d not show anger towards Avraham over his strange behavior; He decrees, at the end of this section, “For I know him, that he will command his children and his household after him to observe the way of G-d, to act with justice and judgment, that G-d may bring upon Avraham that which He has said of him.”
(Bereishit 18:19) Rambam (Laws of Knowledge, chapter 1) interprets this pasuk to mean that the “way of G-d” means following G-d’s ways – “You shall walk in His ways: just as He is called “merciful”, so shall you be merciful – to show that His ways are good and straight, and a person is obligated to conduct himself accordingly.” The Holy One made another covenant with Avraham: that Avraham should continue to follow G-d’s ways and teach his children to do the same, acting with justice and judgment.
Every Jew is obligated to continue to fulfill Avraham’s covenants, through commitment to the Divine commands and to fulfilling them with self-sacrifice like that of Avraham, and through connecting himself to the traits of the Holy One and disseminating them throughout the world, as Avraham did.