John Gill Commentary Ezra 10:12

"Then all the assembly answered and said with a loud voice, As thou hast said concerning us, so must we do." — Ezra 10:12 (ASV)

Then all the congregation answered and said with a loud voice ,
&c.] That they might be heard, and to show that they were willing and ready to comply with what was proposed:

as you have said, so must we do ;
being convinced of their sin, they saw it was a duty incumbent on them to put away their strange wives, and that there was a necessity of it, to avert the wrath of God from them.