To Florus 2.159

The apostle accordingly formed his argument in this way: if none were heirs of the blessing except those who are of the law, then just as the uncircumcised would clearly be excluded, it would follow that no one who was of the law could be deprived of the blessing. In other words, if circumcision had such power that faith was powerless without it, then just as the Gentiles were clearly rejected, it would be proved that no Jew could ever have gone to destruction (compare Romans 4:14).