ערוך לנר מסכת מכות דף יא עמוד ב
בגמרא מיתת כהן הוא דמכפרה. עיין בתוס' (ד"ה מידי גלות) ובריטב"א. ואכתי לפי דבריהם לענ"ד לא מיושב מה דקאמר מידי גלות קא מכפרה, דממנ"פ אם גלות לא מועיל כלל לכפרה למה צריך לגלות, ולמה לא תכפר עליו מיתת כה"ג ג"כ כשיושב בעירו,וכמו שהעיר הריטב"א. ועוד, הרי בפי' אמרינן לעיל ליגלו כי היכי דליהוו להו כפרה וכקושית התוס'.
ואם הגלות מועיל ג"כ לכפרה רק שלא יגמר הכפרה אלא במיתת הכה"ג א"כ אכתי היאך יליף אביי ק"ו ומה מי שגלה כבר וכו' הרי מי שגלה כבר נצטרף כפרת גלות לכפרת כה"ג משא"כ מי שלא גלה עדיין:
והנלענ"ד בזה דשני מיני כפרות יש בזה, כפרת תליי' וכפרה בהחלט. והנה גם באשם תלוי כתיב וכפר עליו הכהן, וכפרה זו ודאי אינה כפרה גמורה דהא אם נודע לו שחטא אחר שהביא אשם תלוי צריך להביא חטאת כדאמרינן בכריתות, א"כ כפרה זו אינה רק כפרת תליי' מן היסורין עד שיודע לו ויביא החטאת שמכפר עליו לגמרי.
כמו כן צריך ברוצח בשוגג כפרת תליי' להגן עליו מן היסורין באשר שחטא חטא גדול כזה שהרג נפש, עד שימות הכה"ג ויתכפר כפרה גמורה. ולכן א"ש דקרי לגלות ג"כ כפרה ומכל מקום א"ש ג"כ ק"ו דאביי, שהרי גם באשם תלוי הדין כן דאם נודע לו שחטא קודם שהביא אשם תלוי אינו מביא רק חטאתו ולא צריך שוב עוד לכפרת אשם תלוי, כמו כן הכא כשבא הכפרה גמורה של מיתת הכהן קודם כפרת תליי' דגלות ל"צ עוד לכפרה זו:
Aruch la-Ner (Ya'akov Ettlinger, Germany, 1798-1871) [personal translation, use at your own risk]
In the Gemara it says, "It is the death of the Kohen Gadol that atones" [as opposed to exile in the City of Refuge]. See the Tosafot and the Ritva [below]....If exile doesn't help at all for atonement, then why require exile [at all]? And why wouldn't the death of the Kohen Gadol effect atonement when dwelling in one's own city, as the Ritva asks...?
If exile also helps effect atonement, but doesn't complete the process of atonement without the death of the Kohen Gadol, then how does the Kal v'homer of Abaye work....?
IMHO, there are two different kinds of atonement [kapara] at work here: suspended kapara and decisive kapara. We find the same for a "suspended-asham" sacrifice, as the verse (Vayikra 5:6) says, "the Kohen shall make kapara for him." This kapara may be definite, but it is not complete kapara. For if it is known to him that he will sin after having brought a suspended-ashem, then he will be required to bring a hattat [sin offering], as it says in Masechet Kritot. This case of kapara is specifically a suspended kapara, pending the experience of suffering, until it is known to him and he brings a hattat ofering that effects complete kapara.
Similarly, in the case of someone who committed negligent involuntary homicide, the atonement is suspended, to protect against the suffering that would other follow from having committed such a huge sin as killing a person, *until* the death of the Kohan Gadol, which effects complete kapara. Therefore, say that one who happens to go into exile, also experiences kapara. Say also the kal v'homer of Abaye, which is just like the suspended-ashem: the rule there too is if it is known to him [the kohen] that the sin was committed before the suspended-ashem could be brought -- then it isn't brought! Only his hattat offering is brought, and there's no further need for kapara from a suspended-asham. Similarly here: once complete kapara comes from the death of the Kohen Gadol, even before the suspended kapara of exile, there is no need for further kapara.
As the Gemara in Yoma and Rambam in Hilchot Teshuva state, for severe enough sins, even completely Teshuvah, plus the day of Yom Kippur, plus suffering, are still only sufficient for a suspended kapara. Complete kapara, in that category of sin, arrives only with the death of the sinner.
But in the not-quite-so-severe case of the Shogeg / Rotzeach (the one who committed involuntary but negligent homicide), either one's own death *or* the death of the Kohan Gadol transforms the suspended-kapara (which includes exile, if that has already begun) into complete kapara. The role of the Kohen Gadol is analogous to the Vidui on Yom Kippur itself, when the Kohen Gadol is able to effect kapara for first himself and his family, then for all the Kohanim, and finally for all of the community of Israel.
Abaye's kol va-homer can be read as emphasizing that only death is sufficient for kapara -- if even one who has endured the suffering of exile is still only in a state of suspended-kapara, then *surely* we would acknowledge that one who hasn't even begun their exile is also only in a state of suspended-kapara.
MISHNA: A sin-offering, which atones for unwitting performance of transgressions punishable by karet, and a definite guilt-offering, which is brought for robbery and misuse of consecrated items, atone for those sins. Death and Yom Kippur atone for sins when accompanied by repentance. Repentance itself atones for minor transgressions, for both positive mitzvot and negative mitzvot. And repentance places punishment for severe transgressions in abeyance until Yom Kippur comes and completely atones for the transgression.
If a person violates a positive command which is not punishable by karet and repents, he will not leave that place before he is forgiven. Concerning these sins, [Jeremiah 3:22] states: "Return, faithless children! I will heal your rebellious acts."
If a person violates a prohibition that is not punishable by karet or execution by the court and repents, Teshuvah has a tentative effect and Yom Kippur brings atonement as [Leviticus, loc. cit. states "This day will atone for you."
If a person violates [sins punishable by] karet or execution by the court and repents, Teshuvah and Yom Kippur have a tentative effect and the sufferings which come upon him complete the atonement. He will never achieve complete atonement until he endures suffering for concerning these [sins, Psalms 89:33] states: "I will punish their transgression with a rod."
When does the above apply: When the desecration of God's name is not involved in the transgression. However, a person who desecrated God's name, even though he repented, Yom Kippur arrived while he continued his repentance, and he experienced suffering, will not be granted complete atonement until he dies. The three: repentance, Yom Kippur, and suffering have a tentative effect and death atones as [Isaiah 22:14] states: "It was revealed in my ears [by] the Lord of Hosts, surely this iniquity will not be atoned for until you die."