Gemara

(R. Elazar): If a bachelor had Bi'ah with a single girl not l'Shem Kidushin, he makes her a Zonah.

60b (R. Yehoshua ben Levi): Protests were made about a Kohen who married a girl who converted before three years of age. Rebbi permitted her (to remain married).

Inference: One who converted before three is permitted to Kehunah.

Question: Perhaps she is forbidden, but if she already married we are lenient!

(Rav and R. Yochanan): A Kohen Gadol may not marry a Bogeres or Mukas Etz. If he married her, he is married!

Answer: There is different, for whomever he will marry is destined to become a Bogeres and a non-virgin during the marriage. A Kohen's wife is not destined to become a Zonah during the marriage!

Rav Safra made this inference, asked this question and gave this answer.

A Kohen married a girl who converted before three. He relied on R. Yakov bar Idi, who heard from R. Yehoshua ben Levi that the Halachah follows R. Shimon.

Rav Nachman bar Yitzchak: Divorce her, or I will remove (your reliance on) R. Yakov bar Idi from you (and excommunicate you to make you divorce her)!

(Mishnah): A regular Kohen may not marry an Ailonis, unless he already has a wife and children;

R. Yehudah forbids even if he has a wife and children, since she is a Zonah;

Chachamim say that only a convert, freed slave, or one who had Bi'as Zenus is a Zonah.

(Rav Huna): R. Yehudah learns from "... they were Mezaneh and did not spread (progeny)" - any Bi'ah that (is with a woman who) cannot procreate is Zenus.

(Beraisa - R. Eliezer): A Zonah is like her name (an adulteress);

R. Akiva says, she is a woman open to have Bi'ah with anyone;

R. Masya ben Charash says, even if her husband was taking her to drink (Sotah water) and he had Bi'ah with her on the way, she becomes a Zonah;

R. Yehudah says, a Zonah is an Ailonis;

Chachamim say that a Zonah is only a convert, a freed slave, or one who had Bi'as Zenus;

R. Elazar says, if two singles had Bi'ah without intent for Kidushin, she becomes a Zonah.

(Rav Amram): The Halachah does not follow R. Elazar.

Kidushin 77a (Mishnah - R. Yehudah): The daughter of a male convert is like the daughter of a Chalal;

R. Eliezer ben Yakov says, if a Yisrael married a convert or a convert married a Bas Yisrael, their daughter is permitted to Kehunah. The daughter of two converts is forbidden to Kehunah;

R. Yosi says, even the daughter of two converts is permitted to Kehunah.

78a (Beraisa - R. Shimon bar Yochai): If a girl that converted before three years, she is permitted to Kehunah. It says "Keep all the young girls (of Midyan) alive for yourselves", and Pinchas (a Kohen) was among the men;

Chachamim say, you may keep them alive for slaves.

The different opinions among the Tana'im were learned from "(Kohanim will marry...) virgins from the seed of Yisrael" (Yechezkeil 44:22);

R. Yehudah learns, all the (primary) seed (i.e. the father) must be from Yisrael;

R. Eliezer ben Yakov expounds "from the seed of Yisrael" - it suffices if one parent is a Yisrael;

R. Yosi holds that she must be seeded in Yisrael (her parents are Yisraelim);

R. Shimon holds that she must be a Yisraelis when her Besulim (tokens of virginity) were completed (at the age of 3).

Avodah Zarah 36b (Rav Dimi): The Chashmona'im's Beis Din decreed that if a Yisrael has relations with a Nochris he is liable for four counts. It is as if he had relations with a Nidah, slave, (Nisu'in with a) Nochris and a married woman.

(Ravin): They decreed that he is liable for relations with a Nidah, slave, (Nisu'in with a) Nochris and (if he is a Kohen he is liable also for) Zonah.

Rishonim

Rif and Rosh (6:6): The Halachah does not follow R. Shimon, who permits a girl who converted before three years to Kehunah. Rav Nachman forced a Kohen to divorce such a girl. No man should marry an Ailonis, due to Peru u'Rvu. The Mishnah discusses a Kohen to teach that R. Yehudah forbids due to Zonah. R. Elazar says that if two singles had Bi'ah without intent for Kidushin, she becomes a Zonah. The Halachah does not follow him.

Rosh: Chachamim say that a Zonah is only a convert, freed slave, or one who had Bi'as Zenus. Even if she converted before three years she is a Zonah. This is even if she did not have Bi'ah. It is because Mitzriyim (the same applies to all Nochrim) are steeped in immorality. The Halachah follows Chachamim.

Rambam (Hilchos Isurei Bi'ah 18:1): A Zonah is any woman who is not a Bas Yisrael, or a Bas Yisrael who had Bi'ah with a Chalal or a man forbidden to her by an Isur that applies to everyone.

Migdal Oz: The Halachah follows all of the opinions in the Beraisa about what makes a Zonah, except for R. Yehudah and R. Elazar.

Note: The Migdal Oz came to explain the Rambam, but the Rambam (Halachah 2) rules unlike R. Akiva, who says that a harlot is a Zonah!

Rambam (2): If a single woman had Bi'ah, even if she was a harlot who freely has Bi'ah with anyone, even though she is lashed she does not become a Zonah unless she was forbidden to marry him.

Rambam (3): Similarly, a convert or freed slave is a Zonah and forbidden to Kehunah, even if she converted or was freed below three years old, because she is not a Bas Yisrael.

Rebuttal (Ra'avad): She is not a Zonah! The Gemara (Kidushin 78a) disqualifies her because she is not "Mi'Zera Beis Yisrael".

Defense (Magid Mishneh): The Gemara (60b) says that if a girl converted before three is forbidden to Kehunah, if she married he must divorce her. We do not say 'she was destined to become a Zonah during the marriage'. This shows that she is a Zonah. The Rambam holds that the Gemara in Kidushin does not really learn from the verse. If so, it should have asked how we knew the law before Yechezkeil, and answered that it was a tradition from Sinai and the Navi alludes to it. Rather, she is a Zonah mid'Oraisa. Chachamim say that a convert is a Zonah. They do not distinguish when she converted.

Migdal Oz: The Rambam holds that the Gemara in Kidushin (78a) forbids due to Zonah. This was a decree (Avodah Zarah 36b), because Nochrim are suspected of Bi'ah k'Darkah and Lo k'Darkah

Rashba (60b DH Omar): The Isur Zonah (of a convert) is mid'Rabanan. The Tana'im argue about the law mid'Oraisa. It is a Gezeras ha'Kasuv, and Yechezkeil explained it. The Gemara in Yevamos (60b) means 'if you were correct that she is forbidden mid'Oraisa due to Zonah, we would not let her remain married.'

Rambam (3): If a Nochri, slave, Nasin... had Bi'ah with a Yisraelis she becomes a Zonah. Similarly, if a Yevamah had Bi'ah with a stranger she becomes a Zonah. An Ailonis is permitted to a Kohen. She is not a Zonah.

Sha'ar ha'Melech (24, cited in Gilyon ha'Rambam of R. Akiva Eiger): Even though the Rambam (12:24) holds that the Isur Bi'ah with a Nasin is mid'Rabanan, it makes a Zonah. We must say that it is worse than other Shniyos, who do not make a Zonah (Halachah 4).

Rambam (4): One who has Bi'ah with a Shniyah does not make her a Zonah, for the Torah does not forbid her to him.

Poskim

Shulchan Aruch (EH 6:8): A Zonah is any woman who is not a Bas Yisrael, or a Bas Yisrael who had Bi'ah with a Chalal or a man forbidden to her by an Isur ha'Shavah b'Chol. If a single woman had Bi'ah, even if she was a harlot who made herself Hefker, even though she is lashed she does not become a Zonah unless she was forbidden to marry him.

SMaG (cited in Yam Shel Shlomo 6:26 and Beis Shmuel 18): Even though the Halachah follows Chachamim, since the Gemara rules unlike R. Elazar, this connotes that we should be stringent like all the other Tana'im. (R. Akiva forbids a harlot.)

Shulchan Aruch (ibid.): We need not teach that Bi'ah with a Nochri or slave makes a Zonah (this is obvious). Similarly, a convert or freed slave is a Zonah and forbidden to Kehunah, even if she converted or was freed below three years old, because she is not a Bas Yisrael.

Question (Chelkas Mechokek 9): Since the Rambam and Shulchan Aruch say 'a convert or freed slave', why do they begin with 'any woman who is not a Bas Yisrael'? What does the repetition teach?

Answer (Beis Shmuel 15): This teaches that a Nochris is a Zonah whether or not she converted, even if she never had Bi'ah.