133:21 We remember the deceased on Yom Kippur (by reciting Yizkor) because doing so helps our hearts to be broken and humble; also, because the dead themselves require atonement. As it says in the Sifre, “‘Forgive Your nation, Israel’ – this refers to the living – ‘whom You have redeemed’ – this refers to the deceased.'” This shows us that the dead also need atonement, so we pledge charity in their names. Exodus 30:10 says, “atone once a year…” and nearby (Exodus 30:12), it says “they give every person a ransom for his soul.” Charity is effective for the deceased because Hashem examines our hearts and if they were still alive, the deceased would have given charity. Therefore, the living can request to lighten the decree on the deceased, just as King David prayed for Avshalom (see Talmud Sotah 10b). The righteous dead likewise serve as an advocate for their descendants. Yizkor is also recited on the last day of Passover, the second day of Shavuos, and Shemini Atzeres because the Torah reading includes “every person shall give according to his means” (Deuteronomy 16:17). We therefore pledge money to charity and, since our pledges are made in the names of the deceased, they will be remembered for good and we will be remembered for good because of their good deeds. The practice is for one whose parents are alive to leave the shul while Yizkor is being recited. It is likewise the practice for one in the first year after the death of a parent to leave shul at this time.
133:22 If there is a baby to be circumcised on Yom Kippur, the circumcision is done before Ashrei and the bracha on the mitzvah is recited without the usual cup of wine. Our practice is to recite the bracha over a cup of wine and to give a little of it to the baby to taste aside from what we give him while reciting Ezekiel 16:6, “In your blood you shall live.” We do not give it to another child to taste on Yom Kippur, which is stricter than we act on Tisha b’Av. A mohel who usually sucks the blood with wine in his mouth should not sprinkle the wine with his mouth; he should use his hand, then suck the blood by mouth in the normal fashion.