Gemara

(Mishnah): Yochanan Kohen Gadol abolished Viduy Ma'aser.

(R. Yosi b'Rebbi Chanina): He did this because Ma'aseros were not given properly. The Torah says to give Ma'aser Rishon to a Levi, and we give it to Kohanim (Ezra fined the Leviyim).

Yevamos 86a (Beraisa - R. Akiva): Terumah is given to a Kohen, and Ma'aser to a Levi;

R. Eliezer ben Azaryah says, (Ma'aser is given) to a Kohen.

Question: Do we give it to a Kohen, but not to a Levi?!

Correction: Rather, it is given even to a Kohen.

R. Akiva learns from "to the Leviyim." R. Eliezer ben Azaryah holds like R. Yehoshua ben Levi:

(R. Yehoshua ben Levi): In 24 places, Kohanim are called Leviyim. One of them is "Ha'Kohanim ha'Leviyim Benei Tzadok".

R. Akiva says that this cannot apply here, for it says "you will eat it (Ma'aser) in all places". A Kohen cannot eat it in a cemetery.

R. Eliezer ben Azaryah says, this permits eating it outside Yerushalayim, and exempts (from lashes) one who eats it while he is Tamei.

R. Eliezer ben Azaryah used to receive Ma'aser from a certain woman. R. Akiva switched her door to open to a cemetery. R. Eliezer ben Azaryah was displeased.

Question: (It says elsewhere that Leviyim were fined, and others would receive Ma'aser.) Why were the Leviyim fined?

Answer: They did not return to Eretz Yisrael (from Bavel) in the days of Ezra.

R. Yonason and elders argued about who received Ma'aser as a result of the fine. One says that it was given to the poor. The other says that it was given to Kohanim, for a Kohen, when he is Tamei, is like a poor man.

Question: According to the opinion that it was given to the poor, we understand why R. Akiva switched the woman's door to the cemetery (rich Kohanim may not take Ma'aser). But according to the opinion that Kohanim receive it, why did he switch her door?

Answer: He told R. Eliezer ben Azaryah 'if you take it because of the fine, you are entitled to it. If you hold that mid'Oraisa, Kohanim receive it, you are not entitled to it.'

Rishonim

Rambam (Hilchos Ma'aser 1:4): Ezra fined the Leviyim in his time that Ma'aser Rishon will not be given to them, rather, to Kohanim.

Kesef Mishneh: The Rambam's words here and in Hilchos Ma'aser Sheni 11:13 - 'when they used to give Ma'aser Rishon to Kohanim they did not do Viduy') connote that the fine was only in Ezra's generation. The Gemaros connote otherwise! The Rambam learned from the Beraisa, in which R. Akiva says that Ma'aser is given to a Levi, and R. Eliezer ben Azaryah says that it is given to a Kohen. If Ezra's fine still applied, R. Akiva would say that is given to a Levi or Kohen, and R. Elazar ben Azaryah would say only to a Kohen! We find that Ma'aser was given to Leviyim long after Ezra, e.g. R. Gamliel gave it to R. Yehoshua (on a boat, after giving his Terumah to R. Elazar ben Azaryah - Ma'aser Sheni 5:9). A Mishnah (Gitin 30b) discusses lending to a Levi on condition to keep Ma'aser in lieu of payment. We conclude that the fine was only in Ezra's generation. Afterwards, people could give to Kohanim or Leviyim.

Question #1 (Beis Yosef YD 331 DH veha'Rambam (near 19 in Prishah)): Yochanan Kohen Gadol abolished Viduy Ma'aser because people did not give Ma'aser to Leviyim. He was generations after Ezra!

Question #2 (Chazon Ish Demai 2:3 DH bi'Yerushalmi): The Yerushalmi asked (why the Mishnah says to do Bi'ur), for Yochanan Kohen Gadol abolished Viduy Ma'aser. This is difficult for the Rambam according to the Kesef Mishneh, who holds that Ezra's fine applied only to his generation.

Answers (to both questions - Beis Yosef): People were used to giving to Kohanim, and Ezra was unable to stop them. They felt that it was theft to cease to give to Makireihem (the Kohanim they usually gave to). Alternatively, Yochanan's generation held like R. Elazar ben Azaryah, and Yochanan held like R. Akiva. The SMaG holds like the first answer.

Note: According to the second answer, why was Yochanan able to stop recital of Viduy if the generation was sure that they gave properly? Also, the Yerushalmi (brought in Tosfos Chagigah 16a DH Yosi) says that the first argument among Chachmei Yisrael was about Semichah. Three more arose between Hillel and Shamai, and many arose among their Talmidim. R. Yochanan Kohen Gadol was long before this, in the days of the Yevanim!

Question: R. Akiva said 'if you are taking it because of the fine, you are entitled to it...)!

Answer #1 (Beis Yosef): R. Akiva holds that the fine was only in the generation of Ezra. He told R. Elazar ben Azaryah 'according to you, that the fine was permanent, you may collect due to the fine.'

Answer #2 (Chazon Ish Demai 2:3 DH Achar Kach): The Yerushalmi says that in the days of R. Yehoshua ben Levi they sought to stipulate not to give to Kohanim. It seems that Ezra enacted that people may give to Kohanim. After the Churban, Chachamim wanted to end Ezra's enactment, but it was difficult because some say that mid'Oraisa one may give to Kohanim. Nevertheless, Chachamim made it known that it is improper to continue the fine. When the Rambam says that Ezra's enactment was 'in his time', he means until Chachamim discouraged it.

Question (Ri Korkus): Above, the Rambam rules like R. Akiva. Here he says that the fine was to give only to Kohanim, like R. Eliezer! It is clear from Kesuvos (26a) and Chulin (131b) that R. Akiva holds that the fine was to give even to Kohanim. We find that even after Ezra, people gave Ma'aser to Leviyim. Some say that the fine was not to give to rich Leviyim, but one may give to poor Leviyim. The Rambam disagrees.

Note: It is not clear to me where the Rambam rules like R. Akiva. He says (Halachos 3) that Kohanim must separate Ma'aser Rishon, in order to separate Terumas Ma'aser, without prefacing 'even though Kohanim do not receive Ma'aser from Yisrael, they may keep the Ma'aser that they themselves separate. He did say Stam that Ma'aser is given to Leviyim. The Ri Korkus said 'even after Ezra, people gave Ma'aser to Leviyim.' It seems that he holds that the Rambam holds that the fine was permanent.

Rambam (13): When they used to give Ma'aser Rishon to Kohanim they did not do Viduy.

Poskim

Shulchan Aruch (YD 331:19): After taking Terumah Gedolah, one takes a tenth of the remainder for Ma'aser Rishon. He gives it to a Levi (Rema - some say, even to a Kohen).