The Torah portion of Lech Lecha1 relates how G‑d commanded Avraham to circumcise himself and the members of his household. By doing so, Avraham became the first and primary individual2 to adopt the sign of the holy covenant that exists between G‑d and every Jew.

This connection between circumcision and Avraham is so strong that the blessings for circumcision include the phrase: “to enter him into the covenant of Avraham, our father,” i.e., the circumcision currently taking place is directly related to our patriarch Avraham. Since Avraham is our father,he makes it possible for all of us, his children, to inherit the privilege of entering into an eternal covenant with G‑d.

This kind of inheritance is not at all dependent on any preparations or qualifications on the part of the inheritor — a one-day old infant can inherit everything. Moreover, such inheritance does not even entail a change of ownership;3 the inheritor merely takes the place of the legator.4

So, the covenant made by each and every Jew is the actual covenant of Avraham , since the ability of all Jews to enter into it comes as an inheritance from their father Avraham.

The following, however, must be understood: In explaining the commandment of circumcision, the Rambam states:5 “We do not engage in circumcision because our father Avraham, of blessed memory, circumcised himself and his household, but rather because G‑d commanded us through our teacher Moshe to circumcise ourselves.”

But why then does the blessing read “into the covenant of Avraham, our father,” stressing the connection with Avraham? Would it not be better to say, “into a covenant with G‑d,” thereby emphasizing that the person being circumcised is entering into a Divine covenant, as commanded by the Almighty?

There is something about circumcision that is unlike any other commandment. While all commandments bring about a unification with G‑d, the result of this unification is not usually visible within the body of the one performing the deed; while the hand that distributes charity becomes more spiritually refined through the act, the change is not apparent. Circumcision is unique in that the change brought about by the performance of the commandment becomes a part of the person himself.

In effect, circumcision causes the entire person, even his lowest parts, to be eternally bound to G‑d. Thus, a Jewish child is circumcised at an age when there can be no intellectual desire to fulfill commandments. For an act to affect every fiber of a person’s being, even his lowermost level, it is best to perform it when one is only eight days old.

The reason why the text of the blessing reads “to enter him into the covenant of Avraham, our father,” can be understood accordingly:

It is logical to assume that the performance of circumcision was more difficult for Avraham than for later generations; since he was the first to do so, he had to blaze the trail, as it were.6 But in truth, every Jew who performs circumcision performs it in the same manner as Avraham. The reason for this is that, were circumcision performed as the result of a logical imperative, then the logic behind it would become more readily discernible with the passage of time.

As stated above, however, circumcision is not performed because it is logical to do so; this is why it is performed on a child when he is only eight days old. Therefore, every Jew’s performance of circumcision is entirely similar to Avraham’s — he is verily performing it as a “first,” entering into it in exactly the same manner as did our father Avraham.

Based on Likkutei Sichos, Vol. X, pp. 44-47