The Gemara says that we should not be able to use Lachmei Todah for Matzah, since they are not eaten b'Chol Moshvoseichem. It answers that when the Midkash was in Nov and Giv'on, it was permitted throughout Eretz Yisrael in walled cities, therefore it is eaten b'Chol Moshvoseichem.
But doesn't b'Chol Moshvoseichem include Chutz la'Aretz? It certainly seems that way from other Gemaras, as is evidenced by the words of Tosfos Kidushin 37b DH bi'Zman. We can never eat Lachmei Todah in CHu'l, so why does it qualify as b'Chol Moshvoseichem!
Pesach Feldman, Yerushalayim, Israel
I found your Kashya in the S'fas Emes, just about word for word. Only he first asks it from a S'vara (that even in the time of Nov and Giv'on, Lachmei Todah could only be eaten in Arei Yisrael, but not in Chutz la'Aretz, so how can the Gemara include them in "be'Chol Moshvoseichem")?
Initially he answers that " Moshvoseichem " (your cities) implies Eretz Yisrael, and he supports this with a Gemara in Menachos, which specifically says so in connection with the Sh'tei ha'Lechem. But he concludes with your Kashya from Kidushin, which takes on that it incorporates Chutz la'Aretz too, and what's more, the Gemara there is speaking about Matzah (the very same topic as the Gemara in Pesachim), creating a rather blatant S'tirah.
Refer also to Rashi in Chumash, who, citing the Mechilta (Sh'mos 12:20), precludes Ma'aser Sheini Matzos from "be'Chol Moshvoseichem", in direct contrast to the Gemara in Pesachim. The Zeh Yenachameinu seems to suggest that the Mechilta disputes Resh Lakish's conclusion that Lachmei Todah were eaten in Nov and Givon. It is also possible however, to explain that it holds like the Sugya in Kidushin, that even if they were, it would not be considered "be'Chol Moshvoseichem", seeing as they could not be eaten in Chutz la'Aretz.
I cited earlier the Gemara in Menachos (cited by the S'fas Emes), which precludes Chutz la'Aretz from "be'Chol Moshvoseichem". The same expression is used in connection with Shabbos ("Lo Seva'aru Eish ... "), from which the Gemara in Shabbos precludes the Beis Hamidkash from the prohibition (not the whole of Eretz).
It therefore seems that Chazal learn from "be'Chol Moshvoseichem" whatever is logical. It makes sense to preclude the fire that burned in Meduras Beis Hamokad from the Isur, so they do. Elsewhere (by Matzah), it is more logical for "be'Chol Moshvoseichem" to be taken literally as everywhere, so they do that.
If that is so then bear in mind that Matzah incorporates two different cases, one Mitzvah on the person (Gufo), the other, on the Matzah (Cheftza). Now as far as the former is concerned, it is indeed more logical to include even Chutz la'Aretz (as we are now speaking about the Mitzvah of Matzah without the Pesach). On the other hand, when it comes to the Mitzvah of Cheftza (i.e. the Lachmei Todah), it is more logical to include them, due to the fact that they can be eaten anywhere in Eretz Yisrael, and not just in Yerushalayim (like some other Korbanos).
A better answer still is that the Chachamim include Lachmei Todah from "Moshvoseichem" which implies Eretz Yisrael (like the Gemara in Menachos), whereas they include Matzos in Chutz la'Aretz from "be'Chol", in which case there is no contradiction to begin with.
be'Virchas Kol Tuv
Eliezer Chrysler.