1) This question is asked on Rashi (68b, DH Eved) by the Maharsha (in Mahadura Basra 68b). He does not answer the question.

2) The Tosfos ha'Rosh (68b) is also concerned about what each of the two verses which are mentioned teach us. In fact, the Tosfos ha'Rosh disagrees with Rashi (68b) who cites "Eshes Rei'ehu." This is because the verse "Eshes Rei'ehu" may not be teaching us anything about Kidushin, but rather it is teaching us that the capital penalty does not apply if a Yisrael commited Ni'uf with the wife of an Akum. The Rosh argues that one could have said that even though there is Kidushin for an Akum, there is no capital penalty when Ni'uf is commited with his wife.

3) There is a source for the Rosh in the Gemara in Sanhedrin 52b, "Eshes Rei'ehu Prat l'Eshes Acherim." The Gemara there discusses the capital penalty, which is, of course, the context of Vayikra 20:10.

4) So, for the time being, we can say that the question on Rashi 45a is not difficult, since he could not have cited "Eshes Rei'ehu" because the latter is relevant to the death penalty, not to the actual Kidushin. The verses that Rashi cites (beginning of 45a) are relevant to Kidushin, which fits with the Gemara there which discusses Kidushin.

5) What I have done so far is to show that the difficult Rashi is the one on 68b, not the one on 45a.

6) I looked into this more and would like to add the following. Rashi here (45a, DH Chayavei) cites his source as Kidushin 68b, which derives from Devarim 21:13 (referring to the Yefas To'ar) that "afterwards... she will be your wife," which implies that before she was Jewish the concept of "Havayah" with a wife did not apply. This verse is referring to Kidushin, so it is appropriate to cite this verse at the beginning of 45a where the Gemara is discussing Kidushin for an Akum.

7) The problem is with Rashi to Yevamos 68b, DH Eved, who cites Vayikra 20:10 to prove that there is no Kidushin for an Akum. How can Rashi cite this verse which does not seem to have any connection with Kidushin, but is referring to the capital penalty for adultery with a married woman?

8) However, the Gemara in Yevamos 68b is not the only place in Shas where Rashi cites Vayikra 20:10. In Sotah 26b the Gemara implies that there is no "Havayah" for an Akum; she cannot "be" a wife. Rashi (DH u'Vas) cites again Vayikra 20:10 and Sanhedrin 52b as the source that this excludes the wife of others. Rashi writes that this proves that Akum do not have Ishus.

9) The Netziv, in Meromei Sadeh on Sotah 26b, explains Rashi there, and this can help us understand Rashi in Yevamos 68b as well. The Meromei Sadeh writes that we need two verses because if we would have had only Devarim 21:13 ("and afterwards... she will be your wife"), we would know only that there is no Kidushin for a Yisrael and an Akum woman. The additional verse, Vayikra 20:10, teaches that it works the other way, too; there is no Kidushin for an Akum man and a Yisrael woman.

10) The Meromei Sadeh writes that there is a big difference between Rashi and Tosfos. According to Rashi, there is no Ishus for Akum at all. According to Tosfos (Sanhedrin 52b, DH Prat l'Eshes Acherim), there is an Aseh prohibition of Ishus for Akum but no capital penalty. Therefore, according to Tosfos, there is Ishus when a Nochri man and woman marry.

Dovid Bloom

1) Some Rishonim (Ramban, Rashba, and Nimukei Yosef here)possessed a different text of Rashi.

a) It appears that the Chidushei ha'Ramban did not read in his Girsa of Rashi 45a that Rashi cites any verse as a source that there is no Kidushin for an Akum. The Ramban (beginning of 45a) cites Rashi that Akum are not b'Toras Kidushin, but he writes that Rashi did not write here how we know this. The Ramban continues and writes that later (68b), Rashi wrote that this is derived from "Eshes Rei'ehu," which excludes the Eshes of others.

b) So, according to the Ramban's text in Rashi, there is no contradiction in Rashi since Rashi on 45a cited no verse. If one looks closely at the Chidushei ha'Rashba here, one also notices that according to his Girsa in Rashi no verse was cited here, since the Rashba writes merely that on 68b, Rashi cited "Eshes Rei'ehu." The Nimukei Yosef (who very often merely cites Rashi word by word) also writes here, "v'Oved Kochavim Nami Leisei b'Toras Kidushin," and cites no verse for this. We see, therefore, that according to the Ramban, Rashba, and Nimukei Yosef, there is no contradiction in the way Rashi cites the verses.

c) The Chidushei ha'Ramban continues and asks a question on Rashi on 68b. The verse of "Eshes Rei'ehu" is not sufficient to teach us that there is no Ishus at all for Akum because that verse refers to Akum women! The implication of the Ramban's question is that from the verse "Eshes Rei'ehu" we only have a source that there is no Ishus with Akum women, but we still would not know that there is no Ishus with Akum men. The Ramban answers that we do not need the verse of "Eshes Rei'ehu" to teach about Akum women, since the Gemara in Kidushin 68b cites a different verse for Akum women, namely Devarim 21:13. According to this, Devarim 21:13 teaches that there is no Kidushin with Akum women, while "Eshes Rei'ehu" is now a superfluous verse and can be used to teach that there is no Kidushin with Akum men either.

d) We learn two things from the Ramban. First, we observe again that in the Ramban's Girsa in Rashi 45a the verse Devarim 21:13 was not cited, unlike in our Girsa. Second, the Ramban is a wonderful source in the Rishonim for the Meromei Sadeh that I cited earlier, that Devarim 21:13 teaches that there is no Kidushin with Akum women, while Vayikra 20:10 teaches that there is no Kidushin with Akum men.

2) Let us look at the opinion of the Ramban that a Nochri with a Yisraelis is not considered Giluy Arayos.

a) The Ramban gives another answer to his question on Rashi 68b. The question was that possibly "Eshes Rei'ehu" tells us only that there is no Kidushin with Akum women, but how do we know that there is no Kidushin with Akum men? In my opinion, the second answer of the Ramban gives us a very important rule. He answers that a union between a Yisrael and an Akum woman cannot effect Kidushin because of the prohibition involved between them. Concerning an Akum man and a Yisraelis woman, the situation is different. Why would Kidushin not apply for an Akum man and Yisraelis woman? This is why the verse "Eshes Rei'ehu" is needed -- to teach that Kidushin does not apply also for an Akum man and Yisraelis woman.

b) The Ramban appears to be saying that even without a verse we would know that Kidushin does not hold for an Akum woman and Yisrael man because of the prohibition involved. The verse is only needed for an Akum man and Yisraelis woman. The implication of the Ramban is that no prohibition is involved between the latter two.

c) It seems to me that the Ramban is consistent with his opinion cited in Milchemes Hashem to Sanhedrin (18a of the pages of the Rif) that relations between a Nochri and a Bas Yisrael are not considered Giluy Arayos, while relations between a Yisrael and a Nochris are considered Giluy Arayos. This opinion is also cited by the Ran in Yoma (3b of the pages of the Rif, DH Chutz) in the name of the Ramban in Toras ha'Adam, and by the Rema (Shulchan Aruch YD 157:1) and Gra (YD 157:15) in the name of the Ramban.

d) This opinion of the Ramban is well-known, but I do not think that it is at all well-known that the Chidushei ha'Ramban to Yevamos 45a actually finds support for his opinion in Rashi here. According to the Ramban's Girsa in Rashi here, Rashi never cites Devarim 21:13. In Yevamos 68b, Rashi cites Vayikra 20:10. This means that, according to Rashi, only one verse is necessary to teach that Kidushin does not apply for Akum because a Yisrael man with an Akum woman is Giluy Arayos, and therefore it is obvious that there is no Kidushin so no verse is needed for this. The fact that we do need the verse of Vayikra 20:10 is because an Akum man with a Yisraelis woman is not Giluy Arayos.

3) The answer of the Yashresh Yakov on 68b:

I found, bs'd, that the Yashresh Yakov on Rashi to 68b, DH Iy Hachi (in DH ul'Fi) gives an answer to the contradiction between Rashi on 45a and on 68b: why do we need the verse "Eshes Rei'ehu" since we have already learned from a different verse that there is no Kidushin for Akum? He answers from the Sugya in Sotah 26b that I cited earlier, and he cites Tosfos there (DH Yatza) who writes that "Eshes Rei'ehu" specifically refers to a Yisrael who had relations with a married Nochris. Even though the Gemara in Sanhedrin 57b (second wide line) says in the name of Rav Chananya that there is a concept of "Be'ulas Ba'al" with an Akum (i.e., she is considered to have a husband), nevertheless if a Yisrael had relations with a married Nochris she is not considered for him an Eshes Ish, since she has not had Kidushin.

It seems that the Yashresh Yakov is answering that the verse that Rashi on 45a cites tells us that there is no Kidushin with an unmarried Nochris, while the verse he cites on 68b tells us that there is no Ishus for a Yisrael with a married Nochris either.

Kol Tuv,

Dovid Bloom