Theodoret of Cyrus
As the Prophet approached the end of his life, he called upon the people and urged them to refrain from entering into marriage unions with the indigenous inhabitants of the land, as such unions could lead to wrongdoing.
But if you will embrace the errors of these nations that dwell among you, and make marriages with them, and join friendships:
כִּ֣י ׀ אִם־שׁ֣וֹב תָּשׁ֗וּבוּ וּדְבַקְתֶּם֙ בְּיֶ֙תֶר֙ הַגּוֹיִ֣ם הָאֵ֔לֶּה הַנִּשְׁאָרִ֥ים הָאֵ֖לֶּה אִתְּכֶ֑ם וְהִֽתְחַתַּנְתֶּ֥ם בָּהֶ֛ם וּבָאתֶ֥ם בָּהֶ֖ם וְהֵ֥ם בָּכֶֽם׃
One Church Father comments on this verse
As the Prophet approached the end of his life, he called upon the people and urged them to refrain from entering into marriage unions with the indigenous inhabitants of the land, as such unions could lead to wrongdoing.
Passages read together with this verse.