(Ula): Since the Torah permits Bi'ah b'Miktzas of a Metzora (before his Taharah is complete), it permits Bi'ah b'Miktzas of a Tevul Yom.

Rav Yosef: Ula holds that if most of Bnei Yisrael were Tamei Mes, and they became Zavim, since Tum'as Mes is permitted for Korban Pesach, also Tum'as Zivah.

Question (Abaye): These are different! A Metzora is Hutar (totally permitted to partially enter the Azarah, for it is needed for the Mitzvah. Therefore, also a Tevul Yom may partially enter.) Tum'as Mes is only Dechuyah (overridden to allow Korban Pesach. We have no source to override other Tum'os!)

(Rava): Just the contrary! A Metzora is Hutar, but we have no source to permit partial entry of a Tevul Yom. The Torah was Docheh Tum'as Mes to allow Korban Pesach. Likewise, it is Docheh another Tum'ah (Zivah)!

Avodah Zarah 13a (Beraisa): A Kohen may go to Chutz la'Aretz, even though this makes him Tamei mid'Rabanan, to plead his case, learn Torah, or marry a woman;

R. Yehudah says, if he can find a Rebbi here, he may not become Tamei to learn elsewhere;

R. Yosi permits this, for perhaps he will learn better from the Rebbi there.

Yosef ha'Kohen followed his Rebbi to Tzidon to learn.

(R. Yochanan): The Halachah follows R. Yosi.

Bava Basra 91a (Beraisa): One may not leave Eretz Yisrael (due to inflated prices) until wheat sells for Sa'atayim for a Sela;

R. Shimon says, this is when he cannot afford to buy. If he can afford, even if a Se'ah sells for a Sela, he may not leave.

R. Shimon: Elimelech, Machlon and Chilyon were the leaders of their generation and the philanthropists of their generation; they were punished for leaving Eretz Yisrael - "Va'Tehom Kol ha'Ir...ha'Zos No'omi".

Kesuvos 111a: A Yavam asked if he should go to Chutz la'Aretz to do Yibum.

R. Chanina: His brother died for marrying a Nochris (i.e. a resident of Chutz la'Aretz). Blessed be Hash-m, Who killed him for that. Will the Yavam do the same?!

Kidushin 31b: Rav Asi's mother asked him to find a man as beautiful as himself for her to marry. He fled to Eretz Yisrael. He heard that she was coming after him. He asked R. Yochanan if one may go to Chutz La'aretz. R. Yochanan forbade. He asked if he may go to Chutz La'aretz to greet her. R. Yochanan was unsure. When he saw that Rav Asi came to ask again, he gave him a Berachah (and permitted him to go).

Before Rav Asi reached his mother, she died. She was being brought to Eretz Yisrael for burial. He said that had he known, he would not have left Eretz Yisrael.

Rambam (Hilchos Melachim 5:9): One may leave Eretz Yisrael to go to Chutz la'Aretz only to learn Torah, marry a woman, or save from Nochrim and return to Eretz Yisrael. Similarly, one may leave for business. One may not dwell in Chutz la'Aretz unless the famine in Eretz Yisrael is so severe that wheat sells for twice its usual price. This is when prices are high and people have money. If prices are low but one has no money and no way to earn money, he may go anywhere that he can earn money. Even so, it is Midas Chasidus not to leave. Machlon and Chilyon (Elimelech's sons) were Gedolei ha'Dor, and they left due to a great affliction, and they were Chayav Misah to Hash-m.

Kesef Mishneh: Saving from Nochrim is pleading his case, like it says in Avodah Zarah. The Rambam teaches that even for one of these Heterim, he may not leave permanently. He learns from Kesuvos. It connotes that one may not leave Eretz Yisrael even to marry a woman. In Avodah Zarah, we permit this! The Rambam, like Tosfos in Avodah Zarah, answers that it is permitted only if he intends to return. The Rambam holds that Sa'atayim for a Sela is twice the normal price of wheat.

Birkei Yosef (OC 568:1): If one lives in Eretz Yisrael and desires to prostrate on graves of Tzadikim in Chutz la'Aretz, or he lives in Yerushalayim and desires to go to graves of Tzadikim (elsewhere) in Eretz Yisrael, he may go on condition to return (Pri ha'Aretz 3:6:14, in some editions 3:10:7).

Pischei Teshuvah (YD 372:2): Batei Kehunah Beis Din (23) says that Kohanim who prostrate on the graves of Tzadikim have nothing to rely on. A Medrash says in the name of Eliyahu that graves of Chachamim have no Tum'ah. However, Tosfos says that really, Eliyahu's Heter was due to Mes Mitzvah. In Berachos (19b), we say that Kohanim used to jump over coffins in order to see kings, because it is a Mitzvah, and most coffins have an Ohel of a Tefach above the Mes, so the Tum'ah is only mid'Rabanan. We do not find that there is a Mitzvah or honor to Chachamim to prostrate on graves of Tzadikim. Also, perhaps they were not buried in coffins, or the coffin rotted, and now it is like a closed grave which is Tum'ah mid'Oraisa.

Sedei Chemed (1, Ma'areches Aleph): One may leave Eretz Yisrael to prostrate on the graves of Tzadikim, for it is a great Mitzvah.

Mishpat Kohen (Inyanei Eretz Yisrael 147:1): This is difficult. Granted, we find that Kalev went to prostrate on the graves of the Avos. There are grounds to say that it is a Mitzvah to prostrate on the graves of all Tzadikim. If so, why may one leave Eretz Yisrael to go specifically to graves in Chutz la'Aretz?! One may leave Eretz Yisrael to learn Torah only if he cannot learn in Eretz Yisrael. We rule like R. Yosi who permits leaving only because sometimes one merits to learn only from certain Rebbeyim. This does not apply prostrating on graves of Tzadikim. There is no reason to distinguish between one Tzadik and another. All the more so one should not leave, for the Tzadikim in Eretz Yisrael are greatest. We find that there is a benefit to prostrate on graves of Tzadikim, but I have no source that it is a Mitzvah. Perhaps since Hash-m desires the Tefilos of Tzadikim, it is a Mitzvah to cause the (dead) Tzadikim to pray to arouse Hash-m's desire. Tzadikim are even greater dead than alive! Perhaps one may leave to go to one's parents and Rebbeyim, even though they are not as great as the Tzadikim buried in Eretz Yisrael, since they feel closer to him. Once, a Chacham prostrated near the cave in which R. Chiya was buried, and mentioned that he learns the Tosefta of R. Chiya, so R. Chiya would be more inspired to pray for him (Bava Metzia 85b). However, I cannot fathom that the love of the Avos buried in Chevron would not suffice, to justify going to Chutz la'Aretz, especially if he is a Chacham who will be Batel from Torah.

Mishpat Kohen (ibid., 2): The Sugya connotes that there is no Isur to leave with intent to return. The Heter is needed only for a Kohen. A Yisrael may leave even for Reshus. However, without intent to return is forbidden even in order to marry. This is even if he cannot find a wife in Eretz Yisrael. Perhaps because one who lives in Chutz la'Aretz is like one without a G-d, even a great Mitzvah does not override the Isur to leave. The Rambam says that one may leave for the three Mitzvos, and he returns. This connotes there is no Heter to leave without intent to return. The Kesef Mishneh says that we learn from Avodah Zarah, but there it merely permits a Kohen. What is the source to forbid leaving for other matters with intent to return? Perhaps intent to return permits everything, just like for business! Perhaps the Rambam learns from Kidushin 31b. R. Yochanan did not permit Rav Asi Stam to go to Chutz La'aretz, and did not explicitly permit to go to greet his mother. However, perhaps this is because Rav Asi was a Kohen, but for a Yisrael it would be permitted. This is reasonable. Honoring parents should be no less than business, for which one may leave temporarily! Rather, we must say that also business is permitted only for a Yisrael. A Kohen may leave to save from Nochrim, but not for Stam business. However, Rav Asi asked 'may one leave', not 'may I leave.' This connotes that even a Yisrael may not. Avodah Zarah teaches that to save, even a Kohen is permitted. Perhaps we can prove that even a Yisrael may leave with intent to return only for a Mitzvah, and not for any Mitzvah. Rav Asi said that had he known (that his mother is being brought to Eretz Yisrael for burial), he would not have left. It seems that this is not due to Tum'ah, for a Kohen may become Tamei through other Mesim while engaging in burial of his relative (Nazir 42). The Rambam (Hilchos Evel 2:15) rules like those who forbid. However, the argument is only after he became Tamei, but beforehand, all agree that just like he may become Tamei for his Mes, he may become Tamei through other Mesim if needed in order to bury his Mes. Both are Nidchim (overridden). We do not distinguish Dichuy for one matter or for more, like we find in Zevachim. Tum'ah mid'Oraisa was permitted to Rav Asi, and all the more so Tum'as Chutz la'Aretz. Rather, he regretted Bitul of the Mitzvah of dwelling in Eretz Yisrael, for it takes precedence, since he would fulfill the Mitzvah to become Tamei for her when she arrived.