Sworn unto him, to be true to him in the prosecution of his wicked designs. His son had taken the daughter of Meshullam: this is noted to show the mischief of such unequal and forbidden marriages, and how reasonable and necessary Ezra's action was in the dissolution of them.
Related Commentaries of Nehemiah 6:18
Nehemiah 6:18
18 For there were many in Judah sworn unto him, because he was the son in law of Shechaniah the son of Arah; and his son Johanan had taken the daughter of Meshullam the son of Berechiah.