John Wesley on Romans 2:17

But if thou art called a Jew - This highest point of Jewish glorying, after a farther description of it interposed, Rom 2:17 - 20, and refuted, Rom 2:21 - 24, is itself refuted, Rom 2:25, &c. The description consists of twice five articles; of which the former five, Rom 2:17,18, show what he boasts of in himself; the other five, Rom 2:19,20, what he glories in with respect to others. The first particular of the former five answers to the first of the latter; the second, to the second, and so on. And restest in the law - Dependest on it, though it can only condemn thee. And gloriest in God - As thy God; and that, too, to the exclusion of others.