John Calvin Commentary 2 Corinthians 8:19

"and not only so, but who was also appointed by the churches to travel with us in [the matter of] this grace, which is ministered by us to the glory of the Lord, and [to show] our readiness:" — 2 Corinthians 8:19 (ASV)

Which is administered by us. By commending his ministry, he still further encourages the Corinthians. He says that it tends to promote the glory of God and their kind disposition. Thus it is that these two things are connected—the glory of God and their liberality, and that the latter cannot be given up without the former being proportionally diminished. In addition to this, there is the labor of those distinguished men, which it would be very inconsistent to reject or allow to go unused.