Read Ezra 10:16 Using Other Translations
And the children of the captivity did so. And Ezra the priest, with certain chief of the fathers, after the house of their fathers, and all of them by their names, were separated, and sat down in the first day of the tenth month to examine the matter.
Then the returned exiles did so. Ezra the priest selected men, heads of fathers' houses, according to their fathers' houses, each of them designated by name. On the first day of the tenth month they sat down to examine the matter;
So this was the plan they followed. Ezra selected leaders to represent their families, designating each of the representatives by name. On December 29, the leaders sat down to investigate the matter.