Implied question: The Yerushalmi (Demai 5:1) asked "does Demai really apply to Chalah? A Mishnah (1:3) exempts Chalah of an Am ha'Aretz, and Meduma (a mixture of Terumah and Chulin. If we exempt when a Chaver kneaded for the Am ha'Aretz b'Taharah, we can say that the Mishnah exempts that case!)

Possible answer: [Indeed,] we could have answered that there (the Mishnah) we discuss when the Am ha'Aretz himself separated, for a Chaver fixed (kneaded) for him b'Taharah, like we explain there, for an Am ha'Aretz fears Kodshim.

He would not give something to the Kohen that is not permitted. Here (Demai 5:1), we discuss when the Chaver himself separated [from a dough that he made from Demai];

However, R. Oshaya distinguishes like this there, but the Sugya in 5:1 is like R. Yochanan. He argues with R. Oshaya, and says that both of them are the same. (One is exempt whether an Am ha'Aretz or Chaver separated the Chalah.)

Citation (Yerushalmi, in the name of R. Yosi b'Ribi Chanina) Answer #1: It (the Mishnah) is like Beis Shamai. Also R. Shimon ben Yehudah says in the name of R. Shimon that Beis Shamai obligate [tithing] Chalah [of Demai], and Beis Hillel exempt.

Citation (cont.) Objection: Will you say that Beis Shamai obligate tithing Demai bought for seeding, animals, flour for [tanning] leather or oil for a Ner, i.e. all the leniencies of Demai in Mishnah 1:3!? (They discussed remnants of Menachos. They did not explicitly obligate Chalas Am ha'Aretz.)

If you say that they do, you should say that they argue about all the leniencies of Demai in Mishnah 1:3! Since our Mishnah obligates only Chalah, it is not Beis Shamai.

Citation (cont.) Answer #2: Rather, the case is, he kneaded with fruit juice.

I.e. the Mishnah exempts one who toiled to knead with fruit juice, which was not Huchshar, in order that the dough will be Mekabel Tum'ah. Since he toiled so much, presumably he also tithed.

Citation (cont.) Objection: R. Yosi b'Ribi Chanina said that it is like R. Elazar Ish Bartusa. It is not like Rabanan.

I.e. R. Elazar Ish Bartusa exempt Demai when it was kneaded with fruit juice, but Rabanan disagree. If so, we should not establish the Mishnah like an individual!

Citation (cont.) Answer #3: Rather, we answer like R. Yochanan. It depends on whether it was done b'Tum'ah or b'Taharah. I.e. in Mishnah 1:3 he toiled to get a Chaver to do it b'Taharah, so presumably he fixed it.

Citation (cont.) Answer #4: Rather, it is like R. Elazar.

Explanation: I.e. alternatively, we can answer like R. Elazar. Both Mishnayos discuss b'Taharah. Here we discuss a guest [of the Am ha'Aretz];

In public, he is not believed until he accepts [all stringencies of being a Chaver] in public. Here (5:1) we discuss in public.

Explanation: In Mishnah 1:3, Rabanan are lenient for a guest. This is like a Tosefta in Chalah 1:8.

Citation (Tosefta): One who buys from a baker, or from a woman who bakes to sell in the market, must separate Chalas Demai. A guest of a Ba'al ha'Bayis need not separate Chalas Demai.

Distinction: One must fix Chalah of Vadai Tevel, like the Yerushalmi says;

Citation (Yerushalmi): If one makes a dough from Tevel, whether he separated Chalah before Terumah or vice-versa, what he did takes effect, and one may not eat the Chalah until separating Terumah, and one may not eat the Terumah until separating Chalah.

Explanation: This is not only for a baker. Anyone separates them (Ma'aser Rishon and Ma'aser Oni), and they are his.

Support - Citation (Sotah 48a): (Yochanan Kohen Gadol) enacted that one who buys Peros from an Am ha'Aretz separates Terumas Ma'aser and gives it to a Kohen;

Citation (cont.): He [separates and] brings up Ma'aser Sheni, and eats it in Yerushalayim. Ma'aser Rishon and Ma'aser Oni [he separates and keeps, for] ha'Motzi mi'Chavero Alav ha'Re'ayah.

Implied question: Why don't we say also that Terumas Ma'aser is his, and [even though he may not eat it, for it is Safek Terumah,] he may sell it to Kohanim and keep the money?

Answer: Since it is a small amount, i.e. one part in 100, and also it sells cheaply, since there are few people who may eat it, Rabanan enacted that he give it [for free] to Kohanim. (Also, if he will keep it until he finds a buyer, perhaps a Yisrael will come to eat it.)

Riva's text: Riva's text says eight Kohanim, like it says explicitly in Divrei ha'Yamim (1:5:36), "Azaryah Asher Kihen ba'Bayis Asher Banah Shlomo... Amaryah... Achituv... Tzadok... Shalom... Chilkiyah... Azaryah... Serayah... and Yehotzadak [and he, i.e. Yehotzadak] Halach b'Haglos Hash-m Es Yehudah."

Question: All texts of the Gemara say 18, and the Sifri and Yerushalmi say 18 Kohanim!

Answer: The text of the Seforim is correct. There were nine Kohanim until Yehotzadak, and one Segan (Kohan prepared to substitute for the Kohen Gadol, if necessary) for each Kohen Gadol, making 18 in all.

Support: At the end of Sefer Melachim, it counts the Kohen Gadol and his Segan together - "va'Yikach Rav Tabachim Es Serayah Kohen Rosh v'Es Tzefanyahu Kohen Mishneh."

Question: If so, in Bayis Sheni we should count also the Seganim. If so, there were close to 600! (The Gemara says that there were 300.)

Answer #1: It is proper to say that there were 18 in Bayis Rishon, including the Seganim, l'Ravcha d'Milsa (to cover all possible cases);

Even if you will say that a Pesul occurred one Yom Kipur regarding each Kohen Gadol, and the Segan served in place of him, there were only 18, and all the more so if we say that no Pesul occurred, there were even less;

However, in Bayis Sheni, since [almost] every one did not live the entire year, it says 300, l'Ravcha d'Milsa;

Even if you will say that presumably the Segan did not serve, since he was Kohen Gadol for only one Yom Kipur, it is unlikely that that very day Ones occurred and the Segan served in place of him. Even so, there were at least close to 300 Kohanim.

Answer #2: We can say that the 18 Kohanim were from Pinchas and onwards. Kehunah was given to him and his descendants.

Support (Sifri): "Lachen Emor Hineni Nosen Lo..." teaches that 18 Kohanim Nevi'im descended from Pinchas were in Binyan Rishon, and 80 in Binyan Sheni... Binyan Rishon is from the Mishkan and onwards, until the exile [after the first Churban].

Support (Yerushalmi): Initially, when he and his son and grandson served, 18 Kohanim served. (This connotes from the Mishkan until Bayis Sheni, when Kehunah Gedolah was not hereditary.)

Implied question: It says here "Mikdash Rishon, which stood 410 years, and only 18 served in it"! (This excludes the 479 years of the Mishkan.)

Answer: Because we want to say [for contrast] "Mikdash Sheni, which stood 420 years, and close to 300 served in it", it gives also the count of the years of Bayis Rishon;

However, not all of the 18 Kohanim served in Bayis Rishon. It means that that 18 served in it, i.e. enough Kohanim served in it to complete the count of 18, including those who served beforehand [in the Mishkan].

Support: Divrei ha'Yamim mentions Elazar, Pinchas, Avishu'a, Buki, Uzi, Zerachyah, Merayos, Amaryah, Achituv; Tzadok, Achima'atz, Azaryah, Yochanan, Azaryah, Amaryah, Achituv, Tzadok, Shalom, Chilkiyah, Azaryah, Serayah, and Yehotzadak.

From Avishu'a ben Pinchas until Serayah there are 18 Kohanim, not including Serayah, since he was exiled with Yechanyah. We count among the 18 Kohanim only those who served all their days.

We exclude Serayah, who was exiled with Yechanyah, like it says at the end of Melachim, and Yehotzadak, who was exiled with Tzidkiyahu.

Explanation: R. Yakov said to us in the name of R. Yekusiel ha'Levi of Varmisa that Azaryah was not in the days of Shlomo, rather, in the days of Uziyahu;

Because he was Moser his Nefesh for Avodas Beis ha'Mikdash, when Uziyahu came to serve and was enraged at him, like it says in Divrei ha'Yamim (2:26), it (Shlomo's Mikdash) was called on his name. (The verse says that [only] he served in it.) He was pleased with this Perush.

Support: I later found so in the Perush of Divrei ha'Yamim of the Talmidim of Rav Sadya Gaon.

Note: Tosfos does not mention that Rashi says so in his Perush on Divrei ha'Yamim (1:5:36)! Also Radak (there) brings this in the name of Chazal, without mentioning Rashi. These support that the Perush on Divrei ha'Yamim attributed to Rashi is not Rashi's.

Contradiction: The Sifri and that says that there were 80 Kohanim in Bayis Sheni, and the Yerushalmi says 80, 81, 82 or 83, and our Sugya says 300!

The Sifri and Yerushalmi count only Kohanim who descended from Pinchas.

Explanation: Reish Lakish would not begin to speak with R. Elazar, but if R. Elazar began to speak with Reish Lakish, he would answer;

We find in Zevachim (5a) that Reish Lakish lied on his stomach and asked "if they are Kosher, they should atone..." R. Elazar answered this, and Reish Lakish replied to him.