In the previous post, I provided a Talmudic passage in which Abaye treats Deuteronomy as categorically different then the rest of the Torah. As the following passages show, it seems plausible that an earlier authority shared that opinion.
“And now, O our God, what shall we say after this? For we have forsaken your commandments, which you commanded by your servants the prophets, saying, ‘The land that you are entering, to take possession of it, is a land impure with the impurity of the peoples of the lands, with their abominations that have filled it from end to end with their uncleanness. Therefore do not give your daughters to their sons, neither take their daughters for your sons, and never seek their peace or prosperity, that you may be strong and eat the good of the land and leave it for an inheritance to your children forever.’ - Ezra 9:10-12
In this passage, Ezra denounces intermarriage, a practice that he considered a scourge and fought with all his vigor. Oddly enough, he says that intermarriage was "commanded by your servants the prophets" However, this law was first set down in the book of Deuteronomy (7:3). Why does Ezra appeal to the prophets in his denouncement of intermarriage when an appeal to the Torah itself, or even to the single chief prophet who wrote the law, would carry much more authority?