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Lest haply if they of Macedonia come with me,.... The apostle had determined to come himself, though he was afterwards prevented by Providence, but could not be certain of the coming of the Macedonian brethren with him; however, as it was probable that some of them would come, whose hearts were so much in this work, therefore he judged it fit and proper to send the brethren before hand, in case they should come:

and find you unprepared; not so ready for this service as had been boasted of, and the collection not finished, which had been begun a year ago.

We (that we say not, ye) should be ashamed in this same confident boasting; or "in this same substance", or "subsistence of boasting": a boasting, which, he thought, they had the most solid and substantial ground and foundation to proceed upon; which, should it come to nothing, must cause shame both in the apostles, who had so largely, and with so much assurance, boasted of them; and in the Corinthians, who must be put to the blush, when it should be told them how much they had been boasted of with respect to their readiness, and yet were unprepared: so תוחלת, "hope", expectation, confidence, is rendered by the Septuagint καυχημα, "boasting", Proverbs 11:7 and in Psalms 39:5 υποστασις, the word here used. And some copies, and also the Vulgate Latin version, only read, "in this substance", or glorying, and leave out boasting as superfluous.

Lest haply if they of Macedonia - If any of the Macedonians should happen to come with me, and should find that you had done nothing. He does not say that they would come with him, but it was by no means improbable that they would. It was customary for some of the members of the churches to travel with Paul from place to place, and the conversation was constant between Macedonia and Achaia. Paul had, therefore, every reason to suppose that some of the Macedonians would accompany him when he should go to Corinth. At all events it was probable that the Macedonians would learn from some quarter whether the Corinthians were or were not ready when Paul should go to them.

should be ashamed ...}We (that we say not, ye) should be ashamed ... - “In this,” says Bloomfield, “one cannot but recognize a most refined and delicate turn, inferior to none of the best Classical writers.” Paul had boasted confidently that the Corinthians would be ready with their collection. He had excited and stimulated the Macedonians by this consideration. He had induced them in this way to give liberally, 2 Corinthians 8:1-4. If now it should turn out after all that the Corinthians had given nothing, or had given stintedly, the character of Paul would suffer. His veracity and his judgment would be called in question, and he would be accused of trick, and artifice, and fraud in inducing them to give. Or if he should not be charged with dishonesty, yet he would be humbled and mortified himself that he had made representations which had proved to be so unfounded. But this was not all. The character of the Corinthians was also at stake. They had purposed to make the collection. They had left the impression in the mind of Paul that it would be done. They had hitherto evinced such a character as to make Paul confident that the collection would be made. If now by any means this should fail, their character would suffer, and they would have occasion to be ashamed that they had excited so confident expectations of what they would do.