Verse 17 The apostle having introduced, in a gentle and cautious manner, the principles which show the impossibility that there can be any saving efficacy in a mere ecclesiastical position, now proceeds to give these principles a more direct application to the ideas of the Jews.--Called a Jew; a designation considered by themselves as highly honorable. In modern times, very different associations have become connected with the name.--In the law; in the Mosaic law.--Boast of God; boast of the favor of God.