Albert Barnes on 2 Corinthians 2:9

For to this end also did I write. The apostle did not say that this was the only purpose of his writing, to induce them to excommunicate the offender, he does not say that he wished, in an arbitrary manner, to test their willingness to obey him, or to induce them to do a thing in itself wrong, in order to try their obedience. But the meaning is this: This was the main reason why he wrote to them, rather than to come personally among them. The thing ought to have been done; the offender ought to be punished; and Paul says that he adopted the method of writing to them, rather than of coming among them in person, in order to give them an opportunity to show whether they were disposed to be obedient. And the sense is, "You may now forgive him. He has hot only been sufficiently punished, and he has not only evinced suitable penitence, but also another object which I had in view has been accomplished. I desired to see whether you were, as a church, disposed to be obedient. That object, also, has been accomplished. And now, since everything aimed at in the case of discipline has been secured, you may forgive him, and should, without hesitation, again receive him to the bosom of the church."