Albert Barnes Commentary Ezra 10:3

"Now therefore let us make a covenant with our God to put away all the wives, and such as are born of them, according to the counsel of my lord, and of those that tremble at the commandment of our God; and let it be done according to the law." — Ezra 10:3 (ASV)

Let it be done according to the law - that is, let a formal “bill of divorcement” be given to each foreign wife, by which she will be restored to the condition of an unmarried woman, and be free to marry another husband . The ease of divorce among the Jews is well-known. According to many of the rabbis, a bill of divorcement might be given by the husband for the most trivial cause. Thus, no legal difficulty stood in the way of Shechaniah’s proposition; and Ezra regarded it as necessary for the moral and religious welfare of the people.