John Calvin Commentary 2 Corinthians 9:2

"for I know your readiness, of which I glory on your behalf to them of Macedonia, that Achaia hath been prepared for a year past; and your zeal hath stirred up very many of them." — 2 Corinthians 9:2 (ASV)

For which I have boasted. He shows the good opinion that he had of them from this: that he had, in a manner, stood forward as their surety by asserting their readiness. But what if he rashly asserted more than the case warranted? For there is some appearance of this, inasmuch as he boasted that they had been ready a year before with it, while he is still urging them to have it in readiness. I answer that his words are not to be understood as though Paul had declared that what they were to give was already laid aside in the chest, but he simply mentioned what had been resolved upon among them. This involves no blame in respect of fickleness or mistake. It was, then, of this promise that Paul spoke.