Tosefta su Levitico 9:78

Israelites fulfill their obligation through vow offerings and freewill offerings, and with tithed animals. Kohanim [fulfill their obligation] through sin-offerings and guilt offerings, with first-born [livestock], and with breast and thigh [taken from peace offerings, see Lev. 9:21], but not from bird offerings and not from grain offerings. A Nazirite fulfills [his obligation] with his ram (see Num. 6:14), whether it belongs to him or whether it belongs to others, as long as he eats from the sacrifice all seven [days of the Festival].

[The laws of the sciatic nerve] apply to [ritually] pure [animals] but do not apply to [ritually] impure [animals]. Rabbi Yehuda says, even to impure [animals], because [the sciatic nerve] was forbidden even before the giving of the Torah [and thus predated the laws of purity and impurity]. They said to Rabbi Yehuda, it does not say, "Therefore the Children of Jacob -- Reuven and Simon [etc.] -- do not eat the sciatic nerve," but rather, "the Children of Israel [do not eat the sciatic nerve]" (Gen. 32:33). Those are the ones who stood before Mount Sinai. Rather, why is it written there (i.e., in Genesis, before the Torah was given)? To make it known why it is forbidden. [The laws forbidding eating the] limb of a live animal apply to impure animals as well as pure animals because it was forbidden to both the Sons of Noah (i.e., Gentiles, who are not liable in laws of purity and impurity) as well as to [the Children of] Israel. And [one who eats the sciatic nerve] may be held liable both on account of it being a limb from a live animal and on account of it being from an impure animal [in the event that it was indeed taken from a live and/or impure animal], the words of Rabbi Yehuda. And Rabbi Eliezer and the Sages say, one cannot be held liable except on account of it being a limb from a live animal, as it is said (Deut. 12:23), "You shall not eat the life with the flesh," and thus it is forbidden [to eat the sciatic nerve of a live animal]. On account of "You shall not eat the life with the flesh" they render him liable. This comes to exclude an impure animal, as to which all of it [and not just the sciatic nerve] is prohibited. One who eats the limb of a live animal transgresses a negative commandment. [Relatedly, with respect to one who eats] the fats (as opposed to the flesh) of a live animal, he is liable for transgressing two negative commandments, (1) on account of its [forbidden] fats and (2) on account of it [being from a] live animal. [With respect to] the blood of a live animal, he is liable for transgressing two negative commandments, (1) on account of [the prohibition against eating] blood (Deut. 12:23), and (2) on account of it [being from a] live animal. [The prohibition against eating a] "limb of a live animal" may render one liable on account of [the animal being] carrion. [One who eats the] blood of consecrated animals is liable on account of two negative commandments, (1) on account of [the prohibition against eating] blood, and (2) on account of [the prohibition against a non-priest eating] consecrated animals, the words of Rabbi Yehuda. And the Sages say, he is only liable for transgressing one negative commandment. [One who eats] the fat-tail of consecrated animals (see Lev. 9:18-20) is liable on account of two negative commandments, (1) on account of [eating the] fat-tail, and (2) on account of [eating from] consecrated animals. Rabbi Yehuda renders him liable for transgressing three [negative commandments]: (1) on account of [eating forbidden] fats, (2) on account of consecrated animals, and (3) on account of the fats of consecrated animals.