The Torah in Parashat Ki-Teseh (Debarim 22:6) commands that people from the nations of Amon and Moab are forbidden from marrying into the Jewish nation. Quite obviously, this refers to an Amoni or Moabi who had converted to Judaism, and is thus a full-fledged Jew; if he hadn’t converted, and is still a gentile, then he in any event may not marry a Jew, because he is not Jewish. The Torah instructs that even after an Amoni or Moabi converts and becomes a Jew, he may not marry a Jewish girl. Even generations later, somebody who descends from an Amoni or Moabi may not marry into the Jewish Nation.
The Torah gives two reasons for why members of these nations may not marry into the Jewish People. The first is that they did not bring Beneh Yisrael food and water when they passed near their borders as they traveled from Egypt to the Land of Israel. Secondly, they hired Bilam to place a curse on Beneh Yisrael, showing virulent hatred toward our nation.
The Sefer Ha’hinuch notes that this command shows us the great importance of Hesed, and how severely G-d looks upon miserliness and disregard for people in need. Amon and Moab’s failure to bring food and water to our ancestors, who were weary from travel, is looked upon as a display of evil and cruelty, to the extent that forever more, their descendants are barred from marrying into the Jewish Nation.
The Sefer Ha’hinuch then poses the question of why Amon and Moab are singled out in this respect from other nations who acted cruelly toward Am Yisrael. Egypt oppressed Beneh Yisrael for hundreds of years, and yet, a third-generation Egyptian is permitted to marry into the Jewish People. Why are the descendants of the Egyptians allowed, but the descendants of Amon and Moab aren’t?
The Sefer Ha’hinuch explains that Amon and Moab were guilty of an especially grave “Nebala” (misdeed) – failing to show appreciation. These nations were founded by the sons of Lot, who lived in Sedom and was rescued from the city’s destruction in the merit of Abraham Abinu. The people of Amon and Moab owe their very existence to Abraham Abinu, and they thus owe a debt of gratitude to Abraham’s descendants. Therefore, their failure to show Beneh Yisrael basic sensitivity when Beneh Yisrael passed near their border was considered particularly severe. The Egyptians, by contrast, did not owe Beneh Yisrael anything; in fact, Beneh Yisrael owed them a debt of gratitude for welcoming them to Egypt and supporting them during a time of famine. The Sefer Ha’hinuch writes that the ingratitude shown by Amon and Moab is considered such a grave lack of gratitude that it can never be repaired, and this quality remains forever within these nations and their descendants. Therefore, they are not worthy of marrying into the Jewish People.
Only the males of Amon and Moab are barred from marrying into the Jewish Nation; the women are allowed to marry after they convert to Judaism. The Gemara explains that the women of Amon and Moab were not expected to go out to bring Beneh Yisrael provisions, and this was thus the men’s responsibility. Therefore, only the men are barred from marrying into the Jewish Nation.
This prohibition applied until the time of the Assyrian emperor Sanherib, who conquered much of Eretz Yisrael and all the surrounding lands, and moved populations from one country to the next. After the Assyrian conquests, the people who lived in any given country cannot be assumed to belong to the people who had lived there previously, and can just as easily descend from a different people. Statistically, then, it is more likely that somebody from Amon and Moab actually descends from a different nation. Halacha allows relying on a statistical majority (“Kol De’parish Me’ruba Parish”), and so after Sanherib’s time, men from Amon and Moab are permitted to marry into the Jewish Nation.
The most famous convert from the nation of Moab, of course, is Rut, who married Boaz. We read in Megilat Rut that the first in line, so-to-speak, to marry Rut was a man named Tob, who is referred to anonymously as “Ploni Almoni” (“so-and-so”). He did not wish to marry Rut, and the reason he gave was “Pen Ash’hit Et Nahalati” – this would adversely affect his children (4:6). At first glance, it seems difficult to understand his concern. If a female convert from Moab is allowed to marry into the Jewish Nation, then why would the children born from this marriage have any sort of inferior status? And if this fellow was of the opinion that even the females from Moab were not allowed to marry into the Jewish Nation, then why was he worried only about the children, and not about the forbidden marriage itself?
The Brisker Rav (Rav Yishak Zev Soloveitchik, 1886-1959) explained that the issue at stake hinged on a question regarding the origin of the law which permits marrying a female convert from Amon or Moab. One possibility is that this provision was conveyed to us as a “Halacha Le’Moshe Mi’Sinai” – having originally been taught to Moshe atop Mount Sinai. Another possibility, however, is that the Sages arrived at this conclusion based on the “Shelosh Esreh Middot” – the various exegetical tools with which the Rabbis were authorized to extract Halachot from the text of the Torah. The Brisker Rav noted that there is a critical difference between these two perspectives. If this law was taught as a “Halacha Le’Moshe Mi’Sinai,” then it can never be questioned or challenged. If, however, the Sages in one generation inferred this law through the process of analyzing the Torah text, then the scholars in a subsequent generation could, under certain conditions, dispute their predecessors’ reading of the text. The Brisker Rav thus explained that this “Ploni Almoni” followed the view that the Rabbis inferred this provision based on their analysis of the text, and thus, conceivably, the Sanhedrin in a later generation could reach a different conclusion. The marriage to Rut would then retroactively be considered forbidden, and all the offspring produced by this marriage would be regarded as illegitimate. The truth, however, is that this provision was taught as a “Halacha Le’Moshe Mi’Sinai,” and therefore, it could never be changed. Boaz thus married Rut, realizing that the Halachic basis for permitting this marriage could never be challenged in the future.