I Paul (egō Paulos). Asserts all his personal and apostolic authority. For both words see also 1Th 2:16; 2Co 10:1; Col 1:23; Eph 3:1.
If ye receive circumcision (ean peritemnēsthe). Condition of third class and present passive subjunctive, a supposable case, but with terrible consequences, for they will make circumcision a condition of salvation. In that case Christ will help them not at all.