Jamieson, Fausset & Brown

And that--that is, What I did concerning Titus (namely, by not permitting him to be circumcised) was not from contempt of circumcision, but "on account of the false brethren" (Act 15:1, Act 15:24) who, had I yielded to the demand for his being circumcised, would have perverted the case into a proof that I deemed circumcision necessary. unawares--"in an underhand manner brought in." privily--stealthily. to spy out--as foes in the guise of friends, wishing to destroy and rob us of our liberty--from the yoke of the ceremonial law. If they had found that we circumcised Titus through fear of the apostles, they would have made that a ground for insisting on imposing the legal yoke on the Gentiles. bring us into bondage--The Greek future implies the certainty and continuance of the bondage as the result.