We are in Maseches Yoma, chapter 8, mishnah 8. This mishnah opens the discussion of atonement - the atonement achieved through certain offerings, through Yom Kippur, and through teshuvah itself. We will examine the language of the mishnah and the levels of atonement that emerge from it.
The words of the mishnah:
"Chatas ve'asham vadai mechaprin" - there are a certain number of transgressions for which a person brings a chatas (sin offering), and there are other transgressions for which he brings an asham (guilt offering) known as an asham vadai, a definite guilt offering. These two offerings provide atonement for the sin.
However, they atone only together with the person's teshuvah. And this too was part of the process of the offering itself, since a person would not bring an offering to the Beis HaMikdash unless he had done genuine teshuvah for the transgression for which he was bringing it.
Why is this offering called an asham vadai?
Because there is another type of asham, called an asham talui. An asham talui is an offering that a person brings when he is in doubt as to whether he is obligated to bring a chatas or not. In other words, when a person unintentionally transgresses a prohibition for which one who does it deliberately is liable to kares, he must bring a chatas; but if he is not at all certain whether he transgressed or not, he brings an asham talui.
The reason for its name - talui, meaning suspended - is that it provides only temporary protection from punishment, until it becomes clear whether he actually transgressed. For example: there is a type of fat, cheilev, that is forbidden to eat, and one who eats it deliberately is liable to kares. If a person ate unintentionally and does not know whether it was forbidden cheilev or permitted fat, he brings an asham talui, which protects him as long as the facts remain unclear. The moment it becomes known to him that he did in fact transgress, he must bring a chatas.
For this reason the mishnah does not use the term "atones" regarding an asham talui, but only regarding an asham vadai: an asham vadai provides final atonement for the sin together with teshuvah, whereas an asham talui is merely a temporary measure, until it becomes clear to the person whether he is liable for the transgression or not.
"Misah v'Yom HaKippurim mechaprin im hateshuvah": a person's own death, and likewise Yom Kippur, atone together with his teshuvah.
"Hateshuvah mechaperes al aveiros kalos, al asei v'al lo saaseh": here the mishnah gives more detail. Teshuvah on its own, by itself, provides atonement for lighter transgressions:
Positive commandments - such as a person who did not recite Shema or did not sit in the sukkah.
Negative commandments - prohibitions. The Gemara clarifies that this does not refer to all prohibitions, but to those that are lighter, namely a lav hanitak la'asei - a prohibition that can be rectified by means of a positive commandment. For example: one may not leave over the meat of an offering beyond the time it may be eaten, and if he did so, the positive commandment that rectifies it is the burning of that meat. The precise definition of these prohibitions is those that carry no punishment of lashes, such as a lav hanitak la'asei, and for these teshuvah alone provides atonement.
"V'al hachamuros hi tolah ad sheyavo Yom HaKippurim viychaper": for the more severe transgressions teshuvah only suspends - it holds the person, as it were, in the balance - until Yom Kippur arrives and provides the actual atonement.
The levels of atonement according to the Gemara:
The Gemara clarifies the matter, and it had before it a slightly different version from the version of our mishnah regarding the levels of atonement. What emerges from its discussion in the end is as follows:
If a person deliberately transgressed a positive commandment or a lav hanitak la'asei, or unintentionally transgressed a prohibition that carries lashes (such as eating food that is not kosher), and he did teshuvah - he is forgiven immediately, and teshuvah alone atones for him.
A prohibition that carries the punishment of lashes - teshuvah merely suspends the person, until Yom Kippur arrives and provides complete atonement.
A prohibition that carries kares or death at the hands of beis din, transgressed unintentionally - he brings a chatas, and this too together with teshuvah.
If he transgressed one of these severe prohibitions deliberately - teshuvah and Yom Kippur only suspend, and suffering, meaning the trials, troubles and difficulties a person goes through in life, is what actually provides the atonement.
The final level is a person who is guilty of chillul Hashem, the desecration of the name of the Holy One, blessed is He: even teshuvah, Yom Kippur and suffering do not atone for him completely, until the person's death. At that point there can be full atonement even for the transgression of chillul Hashem.
In summary: in this mishnah we learned the levels of atonement: the chatas and the asham vadai atone together with teshuvah, while the asham talui is only a temporary protection until the facts become clear; death and Yom Kippur atone together with teshuvah; teshuvah alone atones for the lighter transgressions, and for the severe ones it suspends until Yom Kippur comes and atones. And in the ladder of levels presented in the Gemara: from immediate atonement through teshuvah, through Yom Kippur and suffering, up to chillul Hashem, whose atonement is completed only through death.