עברות שבין אדם למקום, יום הכפורים מכפר. עברות שבין אדם לחברו, אין יום הכפורים מכפר, עד שירצה את חברו.
Yom Kippur atones for transgressions between a person and God, but for a transgression against one's neighbor, Yom Kippur cannot atone, until they appease their neighbor.
אמר ר' יצחק אמרי במערבא משמיה דרבה בר מרי בא וראה שלא כמדת הקדוש ברוך הוא מדת בשר ודם מדת בשר ודם מקניט את חבירו בדברים ספק מתפייס הימנו ספק אין מתפייס הימנו וא"ת מתפייס הימנו ספק מתפייס בדברים ספק אין מתפייס בדברים אבל הקב"ה אדם עובר עבירה בסתר מתפייס ממנו בדברים שנאמר (הושע יד, ג) קחו עמכם דברים ושובו אל ה'
Rabbi Yitzhak said: "They said in the West in the name of Rabbah, son of Mari: 'Come and see that God's character is not like that of (a person of) flesh and blood. This is the character of (a person of) flesh and blood: If one angers their fellow with words, it is doubtful whether that person can be appeased by them or not. And even if you say they can be appeased, it is doubtful whether they can be appeased merely with words or not. But God, even if a person commits a transgression in secret, is appeased by them merely with words. As it is said: "Take with you words, and return to the Lord." (Hosea 14:3)
Rabbi Yitzhak said: "One who angers their fellow, even merely through words, must appease them. As it is said: 'My son, ...you are ensnared by the words of your mouth. Do this now, my son, and be saved, since you are at another's mercy: Go, humble yourself and beg your neighbor.' (Proverbs 6:1-3)" If you have financial means, open the palm of your hand to them. And if not, gather many others around them. Rabbi Yossi, son of Hanina, said: "One who begs a favor of their fellow should not ask it of them more than three times. As it is said: 'Please, forgive please...and now please forgive.' (Genesis 50:17)" And if the one against whom they had sinned has died, they should bring ten people and stand them around their grave and say: "I have sinned against the Lord, the God of Israel, and against so-and-so whom I have injured."
ר' ירמיה הוה ליה מילתא לר' אבא בהדיה אזל איתיב אדשא דר' אבא בהדי דשדיא אמתיה מיא מטא זרזיפי דמיא ארישא אמר עשאוני כאשפה קרא אנפשיה (תהלים קיג, ז) מאשפות ירים אביון שמע ר' אבא ונפיק לאפיה אמר ליה השתא צריכנא למיפק אדעתך דכתיב לך התרפס ורהב רעיך
Rabbi Abba once had a grievance with Rabbi Yirmiyah. He (Rabbi Yirmiyah) went and sat down at Rabbi Abba's door. When the maid poured out water, some drops touched his head. He said: "They have made me like a dung-heap!" He recited this passage about himself: "God raises the needy from the dung-heaps." (Psalms 113:7) Rabbi Abba heard and went out to face him and said to him: "Now, I must come forth to appease you! As it is written: 'Go, humble yourself and beg your neighbor.'" (Proverbs 6:3)
When Rabbi Zeira had a grievance with a certain person, he would pass by them repeatedly and show that he was willing to reconcile, so that they would come out and appease him.
Rav once had a grievance with a certain butcher. The butcher did not come before him (to reconcile). On the eve of Yom Kippur he [Rav] said: "I will go to appease him." Rav Huna met him and asked him: "Where are you going, Master?" He said: "To appease so-and-so." He (Rav Huna) said (to himself): "Abba is about to cause someone's death." Rav came and stood over the butcher, who was sitting and chopping an animal's head. He raised his eyes and said to him: "You're Abba!? I have no grievance with you." [Also possibly: "I will have nothing to do with you" or "I have nothing to say to you."] While he was chopping the head, a bone flew off, struck him in the throat, and killed him.
רב הוה פסיק סידרא קמיה דרבי עייל אתא ר' חייא הדר לרישא עייל בר קפרא הדר לרישא ,אתא ר"ש ברבי הדר לרישא ,אתא ר' חנינא (בר) חמא אמר ,כולי האי נהדר וניזיל ,לא הדר ,איקפיד ר' חנינא אזל רב לגביה תליסר מעלי יומי דכפורי ולא איפייס ,והיכי עביד הכי ,והאמר ר' יוסי בר חנינא ,כל המבקש מטו מחבירו אל יבקש ממנו יותר משלש פעמים ,רב שאני ,ור' חנינא היכי עביד הכי ,והאמר רבא ,כל המעביר על מדותיו מעבירין לו על כל פשעיו ,אלא ר' חנינא חלמא חזי ליה לרב דזקפוהו בדיקלא וגמירי דכל דזקפוהו בדיקלא רישא הוי ,אמר ,שמע מינה בעי למעבד רשותא ,ולא איפייס כי היכי דליזיל ולגמר אורייתא בבבל
Once Rav was expounding upon a Biblical text before the Rabbis, and there entered Rabbi Hiyya. Rav returned to the beginning and began again. Bar Kapara entered. Rav returned to the beginning and began again. Rabbi Shimon, the son of Rabbi, entered. Rav returned to the beginning and began again. Rabbi Hanina, the son of Hama, entered. Rav said: "All this continually going back! Let's go!!" He did not return to the beginning. Rabbi Hanina was angry. Rav went to him on thirteen eves of Yom Kippur, but could not appease him. But how could Rav do so? Didn't Rabbi Yosi, the son of Hanina, say: "One who requests a favor from their fellow should not request it from them more than three times"? Rav is different. And how could Rabbi Hanina withhold forgiveness? Didn't Rabba say: "One who overlooks their own honor, all their transgressions are overlooked"? Rather, Rabbi Hanina had seen in a dream that Rav was being hanged from a date tree. And everyone knows that one who is hanged from a date tree (in a dream) will become head of an Academy. He (Rabbi Hanina) said (to himself): "Derive from it that authority will be given to him." And so he would not be appeased, so that Rav would go to teach Torah in Babylon.