창세기 17:26 해설: Rashi, Chizkuni, Da'at Zekenim & Ramban

בעצם היום הזה ON THE SELFSAME DAY when Abraham completed his ninety-ninth year and Ishmael his thirteenth year נמול אברהם וישמעאל בנו WAS ABRAHAM CIRCUMCISED AND ISHMAEL HIS SON.

בעצם היום הזה, on the very same daywhen G-d had issued the command;

בעצם היום הזה, “on this very day;” According to Rabbi Gamliel, Avraham sent a messenger to Shem, son of Noach, and invited him to circumcise him and his son Ishmael. Not only that, but the date was the tenth of Tishrey, i.e. Yom Kippur which during that year occurred on a Sabbath. He derived this from the use of the expression בעצם היום in Leviticus 23,29. [Presumably Avraham knew that performance of this commandment on the eighth day of a newborn child overrides the prohibitions of the Sabbath and even Yom Kippur. Ed.] This is why every year on the recurrence of that date, G–d reminds Himself of Avraham’s having performed this commandment and it is a factor contributing to atoning for all of our sins on that Day. In B’reshit Rabbah, there is a version describing that after Avraham had already had the knife and his foreskin in his hand to perform the circumcision on himself, he became afraid that he might tremble due to his advanced age. G–d thereupon assisted him and guided his hand; this is why we say in our daily prayers in the morning when relating to this event: וכרות עמו הברית, “He cut the covenant with him (Avraham).” The quotation is based on Nechemyah 9,8. The usual translation of the word, inaccurate is: ”He concluded” Ed.]