But neither they themselves that are circumcised
That is, the pleaders for, and preachers of circumcision, whether they themselves were actually circumcised, or not; it means those that were of the circumcision, on that side of the question, whether heartily or not:
keep the law;
of circumcision, as persons may preach up that, which they themselves do not practise; as did the Pharisees, the predecessors of these men; or if they did keep the law, and submit to it, yet this might be done, not out of regard unto it, and zeal for it, but for some other end; as Simon Magus submitted to baptism, and others preached Christ of envy and contention, and not of good will; or if they did do it in obedience to the law, yet this was not keeping the whole law, which circumcision obliged to; and which, unless they did so keep it, would signify nothing; and this no man is capable of keeping perfectly, and consequently no righteousness, life, and salvation, can be had hereby: besides, though these men were so zealous for the lighter matters of the law, the rites and ceremonies of it, as circumcision they disregarded the weightier and more material parts of it, as judgment, mercy, and faith; these they kept not, nor attended to: and many of them lived very dissolute lives and conversations, at least secretly, if not openly; which abundantly proved that they were far from keeping the law; and that their pleading for it, and submitting to some of the rituals of it, were not out of pure love and strict regard to it, but for some other end:
but desire to have you circumcised, that they may glory in your
that is, in the circumcision of it; or, as the Ethiopic version, "in your bodies". Their view in bringing persons to submit to circumcision was, that they might have occasion to glory among the Jews, and boast to them of the numbers of proselytes they brought, and of the service they did to Judaism, and so increase their fame and glory among them.