The Eighth Trial and the Blood of Abraham's Covenant

(Genesis 17:1) The eighth trial. "And Abram was ninety-nine years old." The Holy One, blessed be He, said to him: until now you were not whole before Me, but circumcise the flesh of your foreskin and be whole, for the foreskin is a disgrace, as it says "for it is a disgrace to us" (Genesis 34:14), and the foreskin is the most impure of all impurities, as it is said, "for no more shall there come into you the uncircumcised and the impure" (Isaiah 52:1). Rabban Gamliel says: Abraham sent and summoned Shem son of Noah, and he circumcised the flesh of his foreskin and that of Ishmael his son. "In the midst of that day" (verse 26) - in the strength of the sun, at midday, on the tenth of the month, on the Day of Atonement. It is written there, "You shall do no manner of work in the midst of this day," and it is written here, "In the midst of this day he was circumcised" (verse 26). And in each and every year the Holy One, blessed be He, sees the blood of the covenant of the circumcision of Abraham our father, and atones for the iniquities of Israel, as it is said, "For on this day He shall make atonement for you."