Paul wants to make it clear that those encouraging circumcision were not thoroughgoing observers of the law. 1 They expected law obedience at certain points, but they themselves were disobedient to the same law. 2 Highlighting the hypocrisy of the Judaizers, he once again affirms that you cannot win God’s favour through your own sinful law obedience. His words are similar to those that Jesus spoke to the Pharisees (see Matthew 23:1–39). He would repeat the same idea at a later stage when he writes to the Christians in Rome (Romans 2:17–24). 3
13 Car les circoncis eux-mêmes n'observent point la loi; mais ils veulent que vous soyez circoncis, pour se glorifier dans votre chair.