…concerning the scope of the biblical ban on intermarriage, close analysis of the sources indicates greater uniformity on this matter than is generally supposed. The tannaim do not generally hold that the Bible contains a universal ban on intermarriage. The attribution of such an idea to an important second-century tanna is the invention of the redactional layer of the Babylonian Talmud. The rabbis understand the Bible to contain only a partial ban on intermarriage (i.e., only certain nations are prohibited). Second, concerning the rationale for the Bible’s partial ban on intermarriage, rabbinic sources of all stripes – early, late, Palestinan, and Babylonian – attribute this ban to the moral-religious danger that such a union poses for the Israelite spouse. For the rabbis, the rationale for the prohibition of intermarriage is neither ritual nor genealogical defilement of Israelites. Nor do we find any echo of the Pauline and early Christian notion of carnal defilement.
Christine E. Hayes, Gentile Impurities and Jewish Identities: Intermarriage and Conversion from the Bible to the Talmud (Oxford: Oxford University Press, 2002), 145-146.