והנותרת ממנה יאכלו אהרן ובניו (צו ו:ט)

The renowned Gaon Reb Yakov Gezuntheit zt’’l, the Rav of Warsaw, once asked a Rebbe that lived in Warsaw: “How can you earn parnassah from Yidden’s aveiros, since you accept ‘Pidyan’ – remuneration from Yidden who come to you for a ‘tikun’ – atonement, for their sins, and you live from the pidyan money?”

The Rebbe replied: “The Kohanim also earned a livelihood from Yidden’s averos.  As the passuk says: והנותרת ממנה יאכלו אהרן ובניו – the Kohanim should eat from the leftovers of the Yidden’s Korban Mincha, which this Korban serves as an atonement for their sins, they also ate from the Korban Chatos – which serves as an atonement for grave aveiros!