"G‑d appeared to Abraham in the Plains of Mamre while he was sitting at the entrance of the tent in the hottest part of the day." (Gen. 18:1)

Since it had been Mamre who had advised Abraham on the matter of his circumcision, he is mentioned here, and G‑d appeared to Abraham on his land. Many people ask how it was possible that Abraham should have consulted with this man about such a question. None of the answers that I have seen have satisfied me. I consider it blasphemous for someone to suggest that Abraham made the performance of the commandment subject to Mamre's advice. All Abraham could have done was to consult with Mamre on how to perform this commandment, since he had also been commanded to circumcise Ishmael and all the members of his household. There was always the chance that members of Abraham's household would refuse to undergo the operation. We have proof of this from Ishmael's boast that he had not refused. Abraham therefore consulted how best to convince all parties concerned to comply with G‑d's command. A person must put his entire being at G‑d's disposal…

The moral lesson to be learned from this is that when one is instructed to fulfill a certain mitzvah, one should consult with a qualified person how best to fulfill it. Abraham already observed all the mitzvoth of the Torah before they became obligatory. He knew that the mitzvah of circumcision would be commanded sooner or later. He consulted with Mamre whether he should perform this mitzvah prior to being commanded, since, unlike other mitzvot, this one could only be performed once in his lifetime, and, as it turns out, is a commandment which very much hinges on performance on time (i.e. at the appropriate time).

"He said, 'Sir, if you would, do not go on without stopping by me.'" (Gen. 8:3)

We learn from here that when one tries to do someone a favor one should describe it in such a way that the recipient feels it is he who is doing the favor by accepting the same. When one creates such an atmosphere, the recipient will not decline; he will not think that the donor will boast about having done him a particular favor. This is why Abraham described himself as in those people's debt if they honored him with their presence...

"...Abraham then complained to Abimelech about the well that Abimelech's servants had taken by force." (Gen. 21:25)

Rabbi Yossi, in the name of Rabbi Chaninah, says that admonition eventually produces a feeling of love for the one who admonishes. We know this from the verse, "Admonish the wise and he will love you." (Proverbs 9:8) Rabbi Yossi firmly believed that any "peace" that does not include admonition is no true peace". (Bereshit Rabbah 54:3) If someone hates someone else in his heart believing that person had somehow committed a wrong against him, he should not nurture hatred in his heart; he should take the matter up with the person concerned so as to restore good relations, by giving the one who did the wrong a chance to apologize. Thus love and harmony will be restored between them. One can never be certain that G‑d is not testing him…

The Binding of Isaac (Gen. 22:1-19) teaches that a person must put his entire being at G‑d's disposal; certainly this is so if it is only a question of one of his limbs and even more so if it be a question of one of his shortcomings, such as the tendency to get up late for public prayer and Torah study. Whenever one finds that one's personal inclination conflicts with the revealed will of G‑d, one must suppress one's own will in favor of doing G‑d's will. When one is confronted with the opportunity to either perform a mitzvah or sin (in a manner not detected by his fellow man), he should ask himself if perchance G‑d is not testing him just as G‑d had tested Abraham. One can never be certain that G‑d is not testing him and should consider this before arriving at any decision. Praiseworthy is the person who constantly reflects on how G‑d would wish him to act.

[Translation and commentary by Eliyahu Munk]