70 Pesachim 5/10 & 6/1-3

(10) [The sacrifice] would be torn open, and the pieces [which were to be sacrificed on the altar] were removed, placed on a large dish, and burned on the altar. [When] the first group had gone out, they [went and] sat on the Temple mount; [when] the second [went out, it sat] in the cheil [a low fence around the Temple, which served as a boundary, beyond which entry to those impure was prohibited]; [when] the third group [finished], it stood [remained] in its place. When it became dark, they [all] went out to roast their Pesach sacrifices.

(1) These things [necessary] for the Pesach sacrifice, push off [the command of abstaining from work on] Shabbat: its slaughtering, the sprinkling of its blood, the pressing of its entrails, and the burning of its chelev [fats around the stomach, intestines, and kidneys of some animals which are forbidden for eating]; but its roasting, and the washing of its entrails, do not push off Shabbat. To carry and bring it beyond the techum [the area around a person or community within which it is permissible to travel on Shabbat], or to cut off its wart, does not push off Shabbat. Rabbi Eliezer says, "The [latter two] push [it] off."

(2) Said Rabbi Eliezer, "Does it not follow logically — if slaughtering an animal which is [forbidden] on account of ‏melakhah [one of thirty-nine types of constructive labor forbidden on Shabbat and festivals]‎ pushes off Shabbat [and is allowed in this instance of the Pesach sacrifice]; these [acts enumerated in the previous mishna], which are [forbidden] on account of ‏shevut‎ [restrictions established by the Sages regarding Shabbat to prevent violation of Torah-level Shabbat prohibitions, and to increase its sanctity], do they not [also] push off Shabbat?" Rabbi Yehoshua said [back] to him, "[The laws concerning the] festival will determine [this case; the Sages] permitted many [prohibitions] on it which are [forbidden] on account of ‏melachah, whilst [they left] forbidden on it [prohibitions which are] on account of shevut‎‎." Rabbi Eliezer said [back] to him, "What is this, Yehoshua? What [sort of] proof is it [to infer] from voluntary [acts on the festival] to [one which is] a commandment [namely, acts surrounding the offering of the Pesach sacrifice]?" Rabbi Akiva responded and said, "The sprinkling [of purifying waters on someone impure from contact with the dead] shall determine [this case]; for it is [also] a commandment, and is [forbidden only] on account of ‏shevut‎, and does not push off Shabbat; [then] you too do not wonder that these, even though they are [associated with] a commandment, and are [forbidden only] on account of ‏shevut‎, that [they] will not push off Shabbat." Rabbi Eliezer said [back] to him, "About it [too] I make the inference; if slaughtering an animal which is [forbidden] on account of ‏melakhah pushes off Shabbat, does it not follow that the sprinkling, which is [only prohibited] on account of ‏shevut‎‎ should [also] push off Shabbat?" Rabbi Akiva said [back] to him, "Or reverse [the logic]; if the sprinkling, which is only prohibited on account of ‏shevut‎ does [nevertheless] not push off Shabbat, does it not follow that slaughtering, which is prohibited on account of melakhah should [also] not push off Shabbat?" Rabbi Eliezer said [back] to him, "Akiva! you have [thus] uprooted that which is written in the Torah, 'between the evenings... at its appointed time,' (Numbers 9:3), whether [that be] on a weekday or on Shabbat." He said [back] to him, "My teacher!, bring me [a verse of the Torah which prescribes] an appointed time for these [acts, even] as [it does] for the slaughtering." [This] general rule did Rabbi Akiva say, "All [‏melakhah‎] which is possible to do from the eve of Shabbat, does not push off Shabbat, [but] slaughtering, which is impossible to do from the eve of Shabbat, pushes off Shabbat."

(3) When may one bring a chaggigah [celebratory offering brought on the three pilgrimage festivals] with [in addition to the Pesach sacrifice]? When [the Pesach sacrifice is brought up] on a weekday, [when those that offer it are] in a state of purity, and [when] it is insufficient [for the number of those that are appointed to eat it]. But when it is [brought up] on Shabbat, [when] it is sufficient [for the persons appointed to eat it], or [when these are] in a state of impurity, we may not bring a chagigah with it.