In Vayikra 16:30, the Torah states, “For this day, he will atone for you, to purify you from all your sins, before Hashem you shall be purified.” In the Mishnah in Yoma (8:9), Rebbe Elazar ben Azariah says that, in fact, the phrase, “before Hashem” actually is applied to “all your sins.” Thus, Rebbe Elazar ben Azariah believes that on Yom Kippur one can only receive atone for sins “before Hashem”, that is, for sins Bein Adam Lamakom. However, sins that are Bein Adam Lachavero cannot be atoned for until the perpetrator asks for forgiveness from the victim.
Another Mishnah in Bava Kama explains that while one may have repaid a person for damages done to him, one must still ask for forgiveness. The Mishnah proves its point from the story of Avimelech. Avimelech was instructed by Hashem to ask Avraham to pray on his behalf after he sinned toward Avraham; therefore, it is incumbent upon a sinner to ask forgiveness from a person he has wronged. On this Mishnah in Bava Kama, Rav Yosef Dov Halevi Soloveitchik asked, why did the Mishnah not quote our Pasuk in Vayikra which would have proved that one must ask his fellow man for forgiveness? Why was the story of Avimelech mentioned at all? Rav Soloveitchik suggests that there are two reasons for asking for forgiveness. One is that Hashem does not forgive a sin that is committed Bein Adam Lachavero unless the perpetrartor asks for forgiveness. The second is that one cannot receive atone for any sin, even those Bein Adam Lamakom, on Yom Kippur unless he has asked for forgiveness from all those whom he has wronged. This is because one cannot only receive atonement for some sins, but rather he must receive a categorical atonement, thus requiring him to be forgiven by all those whom he has wronged so that he can be forgiven for sins committed Bein Adam Lachavero. Then, when one receives forgiveness for sins Bein Adam Lamakom and Bein Adam Lachavero, he receives full atonement for all his sins. Rebbe Elazar ben Azariah may be emphasizing the fact that one must be purified from “all [his] sins,” as the Pasuk states.
May we merit on this Yom Kippur to receive a categorical atonement and to be purified before Hashem.