John Gill Commentary Ezra 10:17

"And they made an end with all the men that had married foreign women by the first day of the first month." — Ezra 10:17 (ASV)

And they made an end with all the men that had taken strange
wives
Finished their inquiry and examination of them:

by the first day of the first month ;
the month Nisan, answering to part of March and April; so that they were three months about this work.