Returning to Egypt
The Mekhilta on Parashat Beshalach announces: 'On three occasions the Torah warns against returning to Egypt. Yet the Jewish people violated this decree and each time was severely punished.' The Mekhilta refers to a pasuk in Beshalach in which Hashem promises that the Egyptians would not be seen again after being drowned in the Red Sea. A second pasuk appears in the description of a king in Parashat Shoftim. The King cannot acquire too many horses for that may encourage a return to Egypt (the ancient center for horse-trading) which Hashem had prohibited. Finally, the tokhacha (rebuke) in Parashat Ki Tavo threatens that we will be sold into slavery and returned to Egypt along the route which Hashem warned us against.
Conceivably, these pesukim could have been interpreted as DESCRIPTIVE rather than NORMATIVE or obligatory. In Beshalach, Hashem assures us of the defeat of the Egyptians, in Shoftim, He bans indulgence in horses to prevent an UNHEALTY but LEGAL return to Egypt and in Ki Tavo the Torah describes the nadir of our suffering in our return to Egypt. None of these pesukim unconditionally PROHIBITS return. In fact, the Bavli does not cite this violation (though the Yerushalmi does). However, based on the Mekhilta's impulse the majority of Rishonim – in one variety or another concluded a prohibition of returning to Mitzrayim.
This conclusion begs a famous question - what warrant or right allowed Jews throughout the ages to reside in Egypt? Jewish residence in Egypt spans the millennia and includes prestigious figures – including none other than the Rambam himself. There are reports that the Rambam signed his correspondence lamenting himself as 'the person who daily violates 3 prohibitions'. However the overwhelming popularity of Egyptian residence among Jews elicited a range of different justifications.
The Semag (in negative commandment 237) claims that subsequent to Sancheriv's repopulation of the Mediterranean crescent (during his reign in the mid-first Temple era), the prohibition to visit Egypt was lifted. Since Egypt no longer contained the original Egyptian populace residence became permissible. In fact, the Rambam (in Hilkhot Issurei Biah chapter 12) allows contemporary Egyptians entry into the Jewish population as converts, despite the Biblical injunction. After all, he reasons, current Egyptians bear no legacy to the ancient community which enslaved us. In fact, the Rambam (in his comments to negative commandment 48 of Sefer Ha-mitzvot) actually describes the prohibition as stemming from contact with the Egyptian population. The Chinukh as well (typically in agreement with the Rambam as to the basis of a mitzva) – in his comments to mitzvah 500 - bases the prohibition upon cultural assimilation.
Many object to this justification on two counts: Firstly it is unclear that Sancheriv's efforts impacted Egyptian demography. The midrash elaborates that Egyptians were ultimately repatriated. Proof is cited from the gemara in Sukka (51b) which attributes the elimination of the Jewish population of Alexandria to their violation of this issue. Since they were clearly punished AFTER Sancheriv's reign, the population of Egypt was evidently restored and the violation reinstated. This could explain the Rambam's lament about living in daily violation. Although he clearly defined the mitzvah as stemming from contact with the Egyptian population, he recognized that the original population had been repatriated.
More importantly, this justification assumes that the issue is based upon contact with the Egyptian populace. While the pasuk in Beshalach does target the actual EGYPTIANS the other two pesukim speak of the COUNTRY of EGYPT. If the issur (prohibition) is defined as returning to the land of Egypt and not as resuming contact with Egyptians, then Sancheriv's actions would be irrelevant.
Rabbi Eliezer from Metz (a medieval author of a book known as Sefer Yereim which enumerates the 613 mitzvot) offers a different defense of the practice of living in Egypt. The Torah prohibits returning to Egypt from Israel and reversing the Exodus process. In a sense the prohibition is HISTORICAL and not CULTURAL. The Exodus process was so seminal that Hashem legislated against its reversal. The communities who migrated to Egypt (with the exception of the Rambam) did so from countries other than Israel and were immune to this prohibition. A slightly different but similar defense is provided by the Ritva in Yoma who claims that the issur applies only when Jews are settled in Israel. In effect the prohibition is not cultural nor even historical but rather Zionistic: To encourage residence in Israel through discouraging it in local but sometimes financially 'more attractive' Egypt. (Barukh Hashem, we have advanced to the redemptive state where this economic reality has been inverted.)
Despite their differences the Ritva and Rabbi Eliezer from Metz each views the prohibition as geographical and not cultural. Sancheriv's population reallocation would not impact the prohibition.
Evidently, there are two different views of this prohibition. The Rambam believes that the prohibition is geared toward immunizing us from the Egyptian culture. As the pasuk in Acharei Mot (Vayikra 18:3) acknowledges, the Egyptian culture displayed a vulgarity which endangered Jewish sanctity. Similarly we were enjoined against actual return to prevent this type of assimilation. By contrast, the simple view (adopted by the Ritva and Rabbi Eliezer of Metz) casts the prohibition as geographic.
Another potential question surrounds the viability of this issur under Jewish conquest of Egypt. The Rambam in Hilkhot Melakhim 5:7-8 claims that under Jewish conquest this prohibition would be lifted. This further confirms the Rambam's view that the prohibition is cultural; under Jewish sovereignty the cultural impact would be less threatening. Presumably, Jewish culture would dominate this society and even unchanged Egyptian vulgarity would be tempered by Jewish culture. If, however, the prohibition were geographic this exemption becomes less likely. Simple conquest would not lift or change the status of the country. For this to occur, the conquest would have to fulfill certain conditions necessary for lands to be annexed to Israel. Presumably the Rambam did not demand these conditions and admitted this exception because he viewed the prohibition as cultural.
Yet another difference concerns a Yerushalmi in Sanhedrin 10:8 which permits temporary return to Egypt for business or other non-residential purposes. This allowance can be justified regardless of the basis of the prohibition. Even if the prohibition is geographic, temporary visitation may not be considered RESIDENCE and should not violate this injunction. However, the Rambam claims that even if a person remains in Egypt permanently he does not receive malkot (lashes) since he has not performed an ACTION (lav she-ein bo ma'aseh). When he descends to Egypt he has not yet violated the prohibition and when he remains in violation he has not executed an action (but has merely remained by inertia). Indeed if the prohibition is cultural this 'schedule' may eliminate the prospect of malkot. The essence of the prohibition occurs during residence and exposure to Egyptian culture. This prohibition develops without any definitive ACTION. Even though an action of migration launches this process it should be considered lav she-ein bo ma'aseh.
By contrast, if we view the prohibition as geographic we may install malkot. Even though time must pass to render this stay as "residential" rather than "itinerant," the essence of the issur has already emerged immediately upon descent. Time must elapse merely to CEMENT this process as "permanent" rather than fleeting. According to the Rambam the duration INTRODUCED the assimilation and INTRODUCED the gist of the issur. According to the other opinion the actual issur was executed through the immediate descent to Egypt. The issur has been carried out through an act of migration – as long as the stay becomes consolidated. This may be classified as lav she-yesh bo ma'aseh and may warrant malkot!