The Sages made an astounding statement about Abraham and the mitzvah of brit milah (circumcision). According to the Midrash (Tanchuma VaYeira 3), Abraham only circumcised himself after consulting with his friend Mamrei.
“Why did God reveal Himself to Abraham on Mamrei’s property? Because Mamrei gave Abraham advice about circumcision.”
Could it be that Abraham, God’s faithful servant, entertained doubts whether he should fulfill God’s command? What special difficulty did circumcision pose that, unlike the other ten trials that Abraham underwent, this mitzvah required the counsel of a friend?
Abraham was afraid that if he circumcised himself, people would no longer be drawn to seek him out. The unique sign of milah would set Abraham apart from other people, and they would naturally distance themselves from him. Additionally, people would avoid seeking his instruction out of fear that Abraham might demand that they too accept this difficult mitzvah upon themselves. As the Midrash in Bereishit Rabbah (sec. 47) says:
“When God commanded Abraham to circumcise, he told God, ‘Until now, people used to come to me; now they will no longer come!'”
This side effect of brit milah deeply disturbed Abraham. It negated the very goal of Abraham’s life and vision — bringing the entire world to recognize “the name of God, Lord of the universe” (Gen. 21:33). If isolated, Abraham would no longer be able to carry on with his life’s mission.
This then was Abraham’s dilemma. Perhaps it was preferable not to fulfill God’s command to circumcise himself. On the personal level, Abraham would lose the spiritual benefits of the mitzvah, but the benefit to the entire world might very well outweigh his own personal loss.
Mamrei advised Abraham not to make calculations regarding a direct command from God. God’s counsel and wisdom certainly transcend the limited wisdom of the human mind.
For his sage advice, Mamrei was rewarded midah kneged midah (in like measure). Since Mamrei respected the ultimate importance of God’ commands, placing them above human reasoning, he was honored with the revelation of divine prophecy on his property.
In fact, Abraham’s fears of isolation were realized. From the time of Isaac’s birth, people began to avoid him. Abraham himself sent away the children of his concubines “from before his son Isaac” (Gen. 25:6), and God commanded him to send away Ishmael.
All of this was the Divine plan. God wanted Abraham to concentrate his energies in educating Isaac. For in Isaac resided the seed for repairing and completing the entire world. It was necessary, however, to first nurture the initial sanctity of the Jewish people. The enlightenment and elevation of the world that Abraham so desired would be realized through the spiritual influence of his children.
(Gold from the Land of Israel, pp. 42-43 . Adapted from Midbar Shur, p. 197)