Those who are circumcised could refer to some of the Gentile Christians in Galatia who decided to get circumcised in response to the teaching of the Judaizers. More likely, however, the Judaizers themselves are in view.1 They are the ones who were circumcised and emphasized the need to keep the old covenant law.
13 Car les circoncis eux-mêmes n'observent point la loi; mais ils veulent que vous soyez circoncis, pour se glorifier dans votre chair.