Keritot, Chapter One, Mishnah Two
Todays mishnah refers to the list of transgressions in yesterdays mishnah.
1) For these [transgressions] one is liable to karet if committed intentionally, and if committed unwittingly to a hatat.
2) If there is a doubt whether he had committed the transgression to an asham talui, except in the case of one who defiled the Temple or its consecrated things, for in that case one is liable in this case to a sliding-scale sacrifice, the words of Rabbi Meir.
3) But the sages say: also the blasphemer [is an exception], as it says: You shall have one law for one that acts in error (Numbers 15:29), this excludes the blasphemer who performs no action.
Section one: One who commits any of the transgressions listed in mishnah is liable for karet if done intentionally and a hatat (a sin-offering) if done unwittingly.
Section two: If he does not know whether he committed the transgression (see the introduction), then he brings an asham talui (a type of guilt-offering, see the introduction). This is true for all of the sins in mishnah one, except for defiling the Temple or its consecrated things, for in that case a person brings a sliding scale sacrifice (see Leviticus 5:2ff). For a sliding scale sacrifice a rich person brings an animal, a poor person brings a bird and a very poor person brings grain.
Section three: The sages hold that there is another exception to who brings a hatat and an asham talui, and that is the blasphemer. When it comes to the hatat, the Torah states, You shall have one law for one that acts in error. The midrashic implication is that in order to be liable for a hatat you must perform an action. Since the blasphemer doesnt do anything, but merely speaks, he does not bring a hatat or an asham talui.