2 Corinthians 2:5 - Matthew Poole's English Annotations on the Holy Bible

The particle if doth not here signify any doubting or uncertainty (for the incestuous person, of whom the apostle here, and in the following verses, speaks, had certainly caused grief both to the apostle, and also the church whereof he was a member). It is as much as although; or the apostle speaketh in this form, because by his repentance his grief was much allayed. But how doth the apostle say, that he had grieved him but in part? Some think he saith so, because the apostle's grief for his sin was now turned into joy by his repentance: others think, that those words, in part, signify that it was not the whole church that had grieved him, but only a part of it, viz. this incestuous person, and those who took part with him. Others say, the apostle saith, in part, to let us know, that it was not a grief to him only, but to them also. The last would bid very fair for the sense of the place, if the apostle had not in his First Epistle, 1 Corinthians 5:2, said that they were puffed up, and had not mourned. So as I judge the second more like to be the sense of the apostle; viz. that it was not the whole church that had grieved him, but a part of it only: and therefore the next words are added, that I may not overcharge you all, that is, that I might not load you all with that imputation, as if you were all involved in it.