John Calvin Commentary 2 Corinthians 10:15

"not glorying beyond [our] measure, [that is,] in other men`s labors; but having hope that, as your faith groweth, we shall be magnified in you according to our province unto [further] abundance," — 2 Corinthians 10:15 (ASV)

In the labors of others. He now reproves more freely the false Apostles, who, while they had set their hand to reaping another man’s harvest, at the same time had the audacity to revile those who had prepared a place for them at the expense of sweat and toil. Paul had built up the Church of the Corinthians—not without the greatest struggle and innumerable difficulties. Those persons afterwards come forward and find the road made and the gate open. So that they might appear as persons of consequence, they impudently claim for themselves what did not rightfully belong to them and disparage Paul’s labors.

But having hope. He again indirectly reproves the Corinthians, because they had hindered his greater progress in advancing the gospel. For when he says that he hopes that when their faith is increased, the scope of his ministry will be enlarged, he intimates that the weakness of faith with which they struggled was the reason why his ministry had been somewhat slowed. “I should now have been occupied with winning new churches, and that too with your assistance, if you had made as much progress as you should have. But now you hinder me by your weakness. I hope, however, that the Lord will grant that greater progress will be made by you in the future, and that in this way the glory of my ministry will be increased according to the rule of the divine calling.” To glory in things that have been prepared is equivalent to glorying in the labors of others; for, while Paul had fought the battle, they enjoyed the triumph.