Starting with the last mishnah (on the bottom of 56:) - the offerings of the first-born, the tithes, Passover sacrifice, and more... in terms of what is eaten by whom. Starting with the first-born and the tithing - where the Gemara finds a source for the details and time frame of these offerings. The sages in these discussions are earlier - Tannaim, not Amoraim - and Rabbi Tarfon himself is a kohen. Which makes him more familiar with the details, perhaps. And Rabbi Yossi HaGelili has some questions for him. With a comparison to the piece-offering. Also, why the Passover sacrifice was eaten only at night and only until midnight (or the midpoint of the dark of the night). And it's another dispute between Tannaim - in this case, Rabbi Elazar ben Azariyah and Rabbi Akiva.