1) DOES A KOHEN LOSE KEDUSHAH WHEN HE BECOMES A "PETZU'A DAKA"?
QUESTION: The Gemara asks whether a Kohen retains his Kedushah of Kehunah or loses his Kedushah when he becomes a Petzu'a Daka. If he loses his Kedushah, he should be permitted to marry a woman to whom an ordinary Kohen is prohibited, such as a Giyores (convert), Gerushah (divorcee), or Zonah (harlot).
What is the Gemara's question? The Mishnah earlier (70a) clearly states that a Kohen who is a Petzu'a Daka may eat Terumah. The fact that he is permitted to eat Terumah shows that he retains the Kedushah of a Kohen. Why, then, does the Gemara here ask whether or not he is permitted to marry a Giyores?
ANSWERS:
(a) The CHELKAS MECHOKEK (EH 5:1) suggests that eating Terumah requires less Kedushah than any other aspect of Kehunah, for even a servant (Eved Kena'ani) of a Kohen may eat Terumah.
This answer is difficult to understand. The servant of a Kohen does not eat Terumah in his own right, but because he is the property of the Kohen. If the Petzu'a Daka loses his Kedushah, neither he nor his servant may eat Terumah. (Perhaps the Chelkas Mechokek means that the relationship of the Petzu'a Daka to his former self, so to speak (before he became a Petzu'a Daka) is no less than the relationship of a servant to his Kohen master.)
(b) The PISCHEI TESHUVAH (EH 5:1) cites the BEIS MEIR who suggests that the Kedushah of a Kohen with regard to matters of marriage is unrelated to the Kohen's right to eat Terumah. The Kohen's right to eat Terumah stems from his Kehunah and not from his Kedushah, while the prohibition to marry certain women stems from his Kedushah, as the Torah explicitly says in its discussion of whom the Kohen may marry (Vayikra 21:6-7).
2) HALACHAH: THE STATUS OF A "PETZU'A DAKA" WITH REGARD TO MARRIAGE
OPINIONS: The Gemara asks whether a Kohen retains his Kedushah of Kehunah or loses his Kedushah when he becomes a Petzu'a Daka. If he loses his Kedushah, he should be permitted to marry a woman to whom an ordinary Kohen is prohibited, such as a Giyores (convert), Gerushah (divorcee), or Zonah (harlot). The Gemara proves that he may marry a Giyores from the fact that a Yisrael who is a Petzu'a Daka may marry a Nesinah, even though an ordinary Yisrael is prohibited from marrying a Nesinah because of the prohibition of "Lo Sischaten Bam" (Devarim 7:3). Just as a Yisrael loses his Kedushas Yisrael when he becomes a Petzu'a Daka, a Kohen also loses his Kedushas Kehunah when he becomes a Petzu'a Daka.
Rava initially rejects this answer on the basis that the prohibition against marrying a Nesinah is not an Isur d'Oraisa but only d'Rabanan, and the Rabanan did not include a Petzu'a Daka in their prohibition against marrying a Nesinah. His allowance to marry a Nesinah is not because he loses Kedushah.
Rava retracts his view and affirms that the prohibition against marrying a Nesinah is an Isur d'Oraisa of "Lo Sischaten Bam." Nevertheless, a Yisrael who is a Petzu'a Daka is permitted to marry a Nesinah, presumably because he loses his Kedushah when he becomes a Petzu'a Daka. Similarly, a Kohen should lose his Kedushah and be permitted to marry a Giyores when he becomes a Petzu'a Daka.
In practice, does a Kohen Petzu'a Daka lose his Kedushah? Also, is a Yisrael Petzu'a Daka permitted to marry a Nesinah?
(a) The RA'AVAD (Hilchos Isurei Bi'ah 16:2) rules in accordance with Rava's conclusion that the Isur of Nesinah is an Isur d'Oraisa and a Petzu'a Daka -- whether he is a Kohen or a Yisrael -- loses his Kedushah and is permitted to marry anyone whose Kedushah is compromised, even a Mamzeres. This also appears to be the opinion of RABEINU TAM (cited by Tosfos to 79a, DH u'Nesinim), the RAMBAN (in MILCHAMOS), and other Rishonim.
(b) However, the BA'AL HA'ME'OR rejects Rava's conclusion based on the Gemara later (79a) which relates that David ha'Melech enacted the prohibition against marrying Nesinim. This implies that the Isur is only mid'Rabanan. Accordingly, the fact that a Yisrael Petzu'a Daka may marry a Nesinah is no proof that he loses his Kedushah. He may be permitted to marry a Nesinah simply because the Rabanan did not include a Petzu'a Daka in their Gezeirah. TOSFOS (79a) cites others who come to the same conclusion. This is also the opinion expressed by RASHI in Kesuvos (29a) and Yevamos (37a). (See Insights to Yevamos 79:2.)
(c) The RAMBAM (Hilchos Isurei Bi'ah 16:2) concludes that a Nesinah is prohibited only mid'Rabanan (as the Ba'al ha'Me'or rules), and a Yisrael Petzu'a Daka is permitted to marry a Nesinah simply because the Rabanan did not include a Petzu'a Daka in their Gezeirah (and not because he loses his Kedushah). Since a Petzu'a Daka retains his Kedushas Yisrael, he may not marry a Mamzeres.
However, the Rambam then rules that a Kohen who is a Petzu'a Daka may marry a Giyores. This ruling clearly implies that a Petzu'a Daka does lose his Kedushah! How are the two contradictory rulings of the Rambam to be understood? If the Rambam maintains that a Petzu'a Daka does not lose his Kedushah, why is a Kohen Petzu'a Daka permitted to marry a Giyores?
The MAGID MISHNEH explains that a Kohen Petzu'a Daka is permitted to marry a Giyores because the prohibition against marrying a Giyores is one which is not "Shaveh ba'Kol" -- it does not apply to all Jewish men, but only to Kohanim.
Perhaps the intention of the Magid Mishneh is that a Petzu'a Daka loses the extra Kedushah which a normal Kohen has, and the loss of this extra Kedushah permits the Kohen to marry a Giyores. However, becoming a Petzu'a Daka does not remove the basic Kedushah of a Yisrael, and therefore he remains prohibited to marry a Mamzeres.
(The commentaries explain that the Rambam reached this conclusion because he understands, like the Ba'al ha'Me'or, that the Gemara later in Yevamos upholds Rava's original statement that a Nesinah is Asur mid'Rabanan. Nevertheless, he still retains the decisive ruling of Rav Sheshes that a Kohen loses his Kedushah, based on logical reasoning if not on proof from the Beraisa.)
HALACHAH: The SHULCHAN ARUCH (EH 5:1) rules like the Rambam that a Kohen loses his Kedushah when he becomes a Petzu'a Daka, and he is permitted to marry a Giyores but not a Mamzeres. The REMA rules like the Ra'avad that a Kohen who is a Petzu'a Daka loses his Kedushah entirely and is permitted not only to a Giyores but even to a Mamzeres.

76b----------------------------------------76b

3) CONVERTS FROM EGYPT, AND THE RULERS OF ROME
QUESTION: Rebbi Yehudah related that his colleague, Minyamin Ger Mitzri (a convert from Egypt) told him that he married a Mitzris Rishonah (a first-generation convert from Egypt), and he plans on marrying his son to a Mitzris Sheniyah in order that his grandson be a third-generation Mitzri who will be permitted to marry an ordinary Jew and fully join the Jewish community.
Why was Minyamin so careful to marry a Giyores Mitzris? He could have married an ordinary Jewess himself, because when Sancheriv conquered the nations he dispersed all of the different peoples (Yeshayah 10:13; Berachos 27a, Yoma 54a). Consequently, those who live in Egypt are not considered original Mitzrim, just as those who line in Moav or Amon are not considered Moavites or Amonites.
ANSWERS:
(a) RASHI in Sotah (9a) cites the Tosefta which is the source of Rebbi Yehudah's statement. Rashi there adds that the Tosefta records that Rebbi Akiva told Minyamin that he was in error. Since Sancheriv mixed up the nations, his status as a Mitzri is in doubt and he himself is permitted to join the Jewish community. This is also the ruling of the RAMBAM (Hilchos Isurei Bi'ah 12:25).
(b) TOSFOS quotes the BEHAG who rules differently. He cites another Tosefta in Yadayim in which Rebbi Yehoshua states that even today, a Jew may not marry a Ger Mitzri because a specific time limit was given for the dispersion of Mitzrayim. In Yechezkel (29:13), the prophet relates that forty years after Mitzrayim will be exiled, they will return to their land. Those forty years have already passed. Therefore, a Ger Mitzri is not the same as a Ger from current-day Moav, Amon, or Edom, whom an ordinary Jew is permitted to marry since the original nations have long been dispersed to other locations.
(c) The MORDECHAI (#71) cites RABEINU TAM who asserts that Sancheriv did not disperse the people of Mitzrayim at all (or the Moavites, whom he left in Moav). He exiled only Amon and the other nations.
The Mordechai adds that this seems apparent from the Gemara in Avodah Zarah (9a) which discusses Antoninus and the Roman kings and calls them "Bnei Edom." If Sancheriv dispersed them, why does the Gemara call them descendants of Edom? It must be that Sancheriv did not disperse every nation.
How do the other Rishonim understand that Gemara?
1. The Mordechai cites the SEMAG (Lo Ta'aseh 104) who explains that offspring of the royal family, "Zera ha'Meluchah," always retain their identity regardless of where the royal descendants are exiled. Therefore, the Gemara calls the rulers of Rome "descendants of Edom" because they were descended from the royal family of Edom and did not lose their identity as a result of exile. (Although Rome "does not appoint a king who is the son of a king" (Avodah Zarah 10a), it could be that the rulers were part of one extended family, and thus they may be called "Zera ha'Meluchah." Alternatively, the official law did not permit an official appointment of the son as king after the father, but the father did make successful efforts to ensure that his son was powerful enough to be able to take the throne after him.)
2. Alternatively, Edom is different from the other nations. The Chachamim had a tradition that the Roman rulers descended from Edom. (See RAMBAN, end of Parshas Balak, Chavel edition. See also IBN EZRA to Bereishis 27:40, who maintains that Rome is a descendent of Yavan, and not of Edom. He apparently understands all of these Gemaras to be allegorical in nature, in the form of Asmachta.)