3. For—Greek, "Yea, more"; "Moreover."
I testify … to every man—as well as "unto you" (Ga 5:2).
that is circumcised—that submits to be circumcised. Such a one became a "proselyte of righteousness."
the whole law—impossible for man to keep even in part, much less wholly (Jas 2:10); yet none can be justified by the law, unless he keep it wholly (Ga 3:10).