‘But I have sent the brethren, that our glorying on your behalf may not be made void in this respect, so that, even as I said, you may be prepared, lest by any means, if there come with me any of Macedonia and find you unprepared, we (that we say not, you) should be put to shame in this confidence.'
So he now assures them that he has not sent the three men because of the church's perceived reluctance to give, but so as to ensure that the church were prepared in readiness for a visit by the Macedonians, who might well visit them when he himself comes to see them. What he does not want is for them to be put to shame if the Macedonians arrived and found no collection ready. This would shame both him and them, him because he has been glorying in their readiness, and them because they will lose face.