Joshua 23:12

Else if ye do in any wise go back, and cleave unto the remnant of these nations, even these that remain among you, and shall make marriages with them, and go in unto them, and they to you:

Else, if ye do in any wise go back, and cleave unto the remnant of these nations. By 'going back' is meant transgression of the divine law; and as marriage connections with the idolatrous Canaanites would present many and strong temptations to transgress it, these were strictly prohibited (Exodus 34:12; Deuteronomy 7:3). With his eye, as it were, upon those prohibitions, Joshua threatens them with the certain withdrawal of the divine aid in the further expulsion of the Canaanites-a threat founded on Exodus 23:33; Numbers 33:55; Deuteronomy 7:16.