Was Moses in a Forbidden Marriage?
To question the legitimacy of someones marriage is to cut right to the bone. That is what happened when a leader of the Tribe of Simeon  a man we later discover went by the name of Zimri ben Salu  faced off against Moses over his assertion that he had a right to marry a Midianite woman. If you say it is forbidden, who permitted for you the daughter of Jethro [who was likewise a Midianite]? There is, however, one huge difference. Moses married his wife Zipporah  indeed a Midianite whom he met at the well, having fled Egypt as a young man  decades before Sinai. At that time, there was no Jewish People or Jewish Law in the real sense that Jewish identity and Torah law came into being after the Revelation at Sinai. Moses wife would have converted to Judaism at the Sinai Revelation. Thus, Zipporah was not a Midianite but a Jew. By contrast, the woman brought before Moses had not joined the Jewish faith, and was thus indeed a Midianite. There is no comparison at all. It is perplexing that someone of Zimris caliber, leader of a tribe, would be capable of making such a ridiculous comparison. Equally surprising is the fact that no one seems to have pointed this out to Zimri and his friends. Moreover, neither the Torah nor the vast canonical texts (such as the Talmud and Midrash) offer this obvious defense against such an absurd and offensive attack. It must be, the Rebbe suggests, that the story is not as we have always thought it to be. The line of criticism that Moses married out of the faith is so absurd that it must mean this is not actually the fault they found in Moses marriage. The Priest and the Convertess The Rebbe offers a novel answer. Moses had the status of a Kohen, and a Kohen is not allowed to marry a convertess. This is because the sacred role of the Kohen meant that he could only marry someone whose purity could be ascertained. A convert had a previous life outside of the Jewish faith, and the culture from which she hailed could not be assumed to have had the appropriate moral values. That is the law, and it applies equally to any convertess. They could not find fault in Moses marriage on the basis of Zipporah being a gentile, because she had converted. But that is exactly what they were criticizing: that Moses had married a convert. Moses had served as the High Priest during the inauguration of the Tabernacle, as the Torah describes in detail. Moreover, there is a debate in the Talmud about whether Moses had the status of a Kohen, and according to the great Talmudic sage Rav, Moses was a high priest from the moment he was appointed to inaugurate the Tabernacle for the rest of his life. Zimris point was that Moses was in an invalid relationship, as a Kohen to a convert, and therefore had no business objecting to his choice of partner. If Moses marriage was in violation of the priestly rules, it would indeed seem hypocritical for him to object to someone else violating the rule against intermarriage. Given that in both cases the women were Midianite just added spice to his barb, even if the exact issue was different in each case. In Moses Defense In reality, the objection to Moses marriage was incorrect. Kohen or not, Moses was already married to his wife when he assumed the priestly role  which changes the situation entirely. Moses had not chosen his wife after he was given the priestly status; he had been married to her for decades by that time. Indeed, the Mishnah  the earliest Jewish code of law  rules that, If a Kohen betroths a widow (which he is ordinarily permitted to do), but is then appointed as Kohen Gadol (High Priest, who may not marry a widow ), he may proceed to marry her. Thus, since Moses was already married to Zipporah there was no issue with him staying married to her, even after he attained the status of a kohen. Zimri had his facts wrong and was using an incorrect understanding of the law to justify his own transgressions. Moses was not in a problematic marriage, while what Zimri was seeking to do was most certainly problematic.