Thou therefore which teachest another, teachest thou not thyself? The οὗν here does not involve an anacoluthon after the reading εἴ δὲ in Romans 2:17, though St. Paul would not have much cared if it had been so.
It serves only to sum up the lengthened protasis, and introduce the apodosis: "If … dost thou then," etc.? In what follows it is not, of course, implied that all Jews who relied on the Law were, in fact, thieves, adulterers, etc.
, but only that the Jews as a nation were no more exempt from such sins than others; and it may be that those specified were not selected by the apostle at random, but as being such as the Jews had a peculiar evil notoriety for at that time.
Thou that preachest a man should not steal, dost thou steal?