레위기 16:30의 주석

כי ביום הזה יכפר, the reason why the other factors mentioned just now are required in addition to the sacrificial service is that if the entire load of achieving atonement were to be placed on the shoulders of the High Priest this would amount only to “downgrading” of the seriousness of the sins which is what the term of כיפור is all about. The individual must prepare himself mentally for obtaining forgiveness from his Maker by these additional measures.

Before Hashem you will be purified. Yom Kippur atones only for those who repent and Hashem obligates each man to purify himself from the sole of his foot to the top of his head from all impurity of iniquity before He atones for them. Therefore, it says, “Before Hashem you will be purified” — in the sense that “before” connotes “previous to” … It furthermore cautions about inner repentance in the heart, which is “before Hashem,” for a matter of the heart is revealed only to Hashem. We should not be like the hypocrites that fast and afflict themselves and pray exceedingly so that they will appear to be righteous, and they seem to be a pure generation in human eyes but they do not cleanse themselves from their inner filth. Therefore it says, “before Hashem you shall purify yourself”.