Now we know that whatsoever things the law says, it says to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God.
All Commentaries on Romans 3:19 Go To Romans 3
John Chrysostom
AD 407
Note that Paul was in the habit of referring to the entire Old Testament as “the law” … for here he calls a psalm “the law.” When he talks about every mouth being stopped, he does not mean that the purpose of their sinning was to shut them up but that the reason they were rebuked was that they might not sin in ignorance. Furthermore, it was not just the Jews he was referring to but the whole of mankind.