Ezra 10:44
All these men had married foreign women, and some of them had children by these wives.

so must we do

Ezra 10:3, 4
So now let us make a covenant before our God to send away all the foreign wives and their children, according to the counsel of my lord and of those who tremble at the command of our God. Let it be done according to the Law. . . .

Nehemiah 13:23
In those days I also saw Jews who had married women from Ashdod, Ammon, and Moab.

Psalm 78:37, 57
Their hearts were disloyal to Him, and they were unfaithful to His covenant. . . .