Tosefta su Levitico 7:78

Rabbi Yehuda says in the name of Rabban Gamaliel, two disqualified loaves of thanksgiving offering (see Lev. 7:12-14) were placed on top of the Temple portico. As long as they were placed [on top of the portico], everyone could eat unconsecrated food [containing leaven]. When one was removed, everyone (i.e., the Kohanim) could eat Terumah [containing leaven]. When both were taken away, they burned this one and that one (i.e., unconsecrated food and Terumah). They burned uncertain Terumah (i.e., Terumah whose purity status is uncertain), impure [Terumah], and pure [Terumah] all together, the words of Rabbi Meir. And the Sages say, uncertain [Terumah was burned] by itself, and pure [Terumah] by itself, and impure [Terumah] by itself. Said Rabbi Shimon, Rabbi Eliezer and Rabbi Yehoshua did not disagree about the pure or about the impure [Terumah], whether we burn this one by itself and that one by itself. About what did they disagree? About uncertain [Terumah] and about impure [Terumah], for Rabbi Eliezer says, this one is burned by itself and that one is burned by itself, and Rabbi Yehoshua says, both [are burned] together. Said Rabbi Yosei, the conclusion does not follow from the proof. [What is the proof?] Meat that was rendered impure by a secondary source of impurity [and then made contact] with meat that was rendered impure by a primary source of impurity, both of them are impure, only that this one is possesses a higher degree of impurity, and that one possesses a lower degree of impurity. And so too with oil that became disqualified [through contact with] a tevul yom (i.e., one who has immersed himself but remains impure until sunset) or [by contact] with a candlestick that was rendered impure through death-impurity -- both of them are impure, only that this one is possesses a higher degree of impurity, and that one possesses a lower degree of impurity. And I say that Terumah that became impure through a secondary source of impurity is burned along with Terumah that became impure through a primary source of impurity, even though we are adding impurity onto impurity. And [with respect to] uncertain [Terumah] and impure [Terumah], I say that if the uncertain is burned along with the impure, its impurity is removed from it. Beit Shammai say, we do not burn pure meat with impure meat, but Beit Hilel permit it.

[If] a beit din ruled at the conclusion of the Sabbath [that the sun had set, thus permitting labor], and then later the sun was seen shining [as may occur, e.g., on a cloudy day], this is not an erroneous ruling but merely a mistake (Yev. 92a:2). [If] a beit din ruled to uproot an entire principle, [such as if] they said, "There is no blood (i.e., laws concerning the blood of a sacrificial animal) in the Torah," "There is no fat (i.e., laws concerning the fats of a sacrificial animal) in the Torah," "There is no piggul (Lev. 7:18) in the Torah," behold, they are exempt (Hor. 1:3). [If] they ruled to nullify part and uphold part, behold, they are liable. How so? [If] they said, "There is blood [in the Torah] but there is no obligation, except as to the blood of a peace offering." [Or if they said,] "There is fat in the Torah but there is no obligation except as to the blood of a peach offering." [Or if they said,] "There is piggul in the Torah but there is no obligation except as to piggul of a peace offering." Behold, [in these cases,] they are liable, as it is said elsewhere (Deut. 17:8, see below), "matter." What does "matter" mean? As is said elsewhere (see Midrash Tehillim 105:1), of part of it, but not all of it. You say, a "matter" is part of it, but not all of it, or is it only all of it? The Torah teaches (Deut. 17:8), "[When any matter is too baffling for you, in justice,] between blood and blood," and not "all the blood" -- "between judgment and judgment," and not "every judgment" -- "between plague and plague," and not "every plague" -- thus, there is no need to say [in accordance] with the first version, but rather [in accordance] with the last version. [Just] as it says here, "matter," and it says elsewhere, "matter," what is "matter," so too it says elsewhere "part of it," but not "all of it." Rabbi Shimon ben Eliezer says in the name of Rabbi Meir, "If six sinned and they are the majority, or seven, even if they are not the majority, behold, they are liable."

We do not bring a thanksgiving offering on the Festival of Matzah (i.e., Passover), because of the chametz that is in it (see Lev. 7:13), nor on Shavuot because it is a Day of Slaughter ("יום טבוח", cf. Tos. Chagigah 2:7, Chag. 17b:2-6; alt. "יום טוב" ("[it is a] Yom Tov"), see Beitzah 19b:2 and GR"A here), but it is brought on the Festival of Sukkot, and one fulfills his obligation [of bringing a Festival offering] with it. Rabbi Shimon says, we do not bring a thanksgiving offering on the Festival of Sukkot, because everything that is brought on the Festival of Matzah [also] is brought on the Festival of Shavuot and the Festival of Sukkot. [Thus] a thanksgiving offering, which is not brought on the Festival of Matzah is not brought either on the Festival of Shavuot or on the Festival of Sukkot. Rabbi Elazar son of Rabbi Shimon says, a thanksgiving offering is brought on the Festival of Sukkot, and one fulfills his obligation of rejoicing with it, but does not fulfill his obligations of [bringing a] Festival offering with it.

A Kohen who takes upon himself all the ritual obligations of the priesthood, except for one thing, we do not accept him. A Levite who takes upon himself all the Levitical obligations except for one thing, we do not accept him, as it is written (Lev. 7:33), "he who offers the blood of the peace-offering, and the fat [of the peace-offering] from among the sons of Aaron shall get the right thigh as his portion." [With reference to Kohanim (following Steinsaltz to Hul. 132b:15 to Hul. 133a:2)], I have only derived [that a Kohen does not share in the priestly gifts] only [if he does not believe in the validity of] sprinkling blood and burning of fats [on the altar]. How do we know [that they are also obligated in the rites of] the pouring [of oil onto the minchah-offering], the mixing [the ingredients together], the waving and bringing [the meal offering to the corner of the altar], the removing the handful and burning [on the altar], cutting [the neck of bird-sacrifices], receiving and sprinkling [the blood], the Sotah ceremony, the breaking the red heifer's [neck], and purifying the metzora [= leper], and the lifting the hands [to bless the people] inside and outside [the Temple]? As the Torah teaches (Lev. 7:33) "[among the] sons of Aaron," that is [to say] "all the rites" that are incumbent upon the sons of Aaron. Said Rabbi Shimon, you might think [lit. "it can be"] we don't prohibit them except from partaking in the priestly gifts within the Temple; how do we know [we also prohibit them partaking in priestly gifts given] in the countryside (see Y. Chal. IV.4.17)? As the Torah teaches (Deut. 18:4), "You shall also give him the first fruits of your new grain [and wine and oil, and the first shearing of your sheep]." Because [as it says, Deut. 18:5], "For the LORD your God has chosen him [etc.]"; thus, everyone who takes upon himself the service, he receives the gifts. All those who do not take upon themselves the service, he does not receive the gifts. During the time that the Kohanim do the will of [their Father in heaven, following the GR"A], what it says about them (Lev. 6:10), "I have given it as their portion from My offerings by fire." What is theirs, they take, and they do not take what is mine. And during the time that they do not do His will, what is said about them (Mal. 1:10), "If only you would lock My doors[, and not kindle fire on My altar to no purpose! I take no pleasure in you—said the LORD of Hosts—and I will accept no offering from you.]"

What is the shankbone? It is taken from the socket and all the socket with it. The "shankbone" of the Temple is the "shankbone" of the countryside. What is the "cheek"? It is taken from the place of the slaughter and the entire place of the slaughter with it. The "maw" is as it implies. The fats that are on the maw are given to the Kohen. Said Rabbi Yehuda, the Kohanim used to behave generously, and they would give it [back] to the owners. The "shankbone" is the right shankbone. You may say, is it the right shankbone, or perhaps it is only the left shankbone? [But] behold, you may deduce, since the [breast and] thigh (Lev. 7:33-34) is a gift to the Kohen, and the shankbone is a gift to the Kohen, since the [gift of the breast and] thigh are only applicable to the right, the [gift of the] shankbone also is only applicable to the right. The thigh is from the joint and downward, the words of Rabbi Yehuda, and the Sages say, from the joint and upwards. What is the "breast"? Whatever faces the ground and upwards, until it reaches the neck, [and] downward until it reaches the belly. Two ribs should be cut off and given [to the Kohen] along with it (i.e., the breast). And these are the sacrificial parts [of the animal]: The two kidneys and the lobe of the liver and that which is attached to it. And these are the [sacrificial] fats: "The fat that covers the innards and all the fat that surrounds the innards" (Lev. 3:3, Fox tr.), those are the fats. [The fats] surrounding the rumen and all the fats that are on the small intestine, the words of Rabbi Yishmael. Rabbi Yishmael says, the fats that are on the maw, and the Sages did not agree with him. [With regard to the fat] that is on the loins between the sinews, one scrapes around it in every place that it is found and takes it away, the words of Rabbi Yosei HaGalili. Rabbi Yishmael says, the fat that is on the maw, which is spread out [and possesses] a membrane, and is [easily] peeled off, is forbidden. Rabbi Yehuda says, the membrane that is on the kidney is forbidden, and one is liable [for eating] it. The sinews that are in the kidneys and in [other] offerings are forbidden, but [bedi'eved] one is not liable for them.