“Shall we then listen to you and do all this great evil and act treacherously against our God by marrying foreign women?" (27). Nehemiah was horrified by how many Jewish men (including priests, v28) had voluntarily married non-Jews, demonstrating how little they cared about living faithfully for God. The prohibition against inter-marriage wasn’t racial (hence the acceptance of Ruth, a Moabitess), but instead religious. Non-Jewish parents wouldn’t raise their children to follow God’s ways, and they might even, like Solomon’s wives, introduce idolatry (v26).
“Did not Solomon king of Israel sin …?” (v26). Solomon didn’t protect the intimate areas of his life and, through his relationships, was led astray. God wants to be the priority and center of our homes.