Por que el assunto de quemar kodashim o truma ao aumentar - le la tum? entra em Pessachim . Como Cabe este assunto en esta massechess ?
Translation: Why does the Gemara digress into the long discussion of the laws of Tuma'ah of kodashim and truma? How does it fit into the subject of this massechess?
Moishe, S. Paulo - Brazil
Rashi already asks your question, and he explains that the Mishnah only cites the Reisha (the opinions of R. Chanina S'gan ha'Kohanim and R. Akiva) because of the Seifa ('Amar R. Meir, mi'Divreihem Lamadnu ... '), which speaks about burning Terumah Tehorah together with Terumah Teme'ah on Pesach, which in turn, is similar to the previous Mishnah, where the Tana'im argue about eating Chametz of Terumah during the fifth hour.
The Tana had to insert the Machlokes between R. Chanina S'gan ha'Kohanim and R. Akiva, because, according to most Amora'im, R. Meir brings his proof from the former. And he had to insert R. Yehoshua and R. Eliezer, because R. Yossi queries R. Meir from them.
According to Resh Lakish, the Mishnah only inserts R. Chanina and R. Akiva, because R. Yossi thought, erroneously, that this was R. Meir's source (see Tosfos, 15a DH 'mi'Divrei'). No matter, the Mishnah had to mention them.
In his opinion, the Tana had to insert R. Eliezer and R. Yehoshua, because R. Meir's proof is from them.
In any event, once the Mishnah found it necessary to mention all six Tana'im, as we just explained, one thing follows the other, and the rest of the Sugya is inevitable.
be'Virchas Kol Tuv