The Apostle Paul
2 Corinthians 9:14ESV·traditional attribution

while they long for you and pray for you, because of the surpassing grace of God upon you.

John Calvin Reformed @genevareformer

14. And their prayer He omits no advantage which may be of any use for stirring up the Corinthians. “Qui puisse seruir a esmouuoir et encourager les Corinthtens.” — “That may serve to stir up and encourage the Corinthians.” In the first place, he has made mention of the comfort that believers would experience; secondly, the thanksgiving, by means of which God was to be glorified.

Matthew Henry Presbyterian @wholebiblehenry

Here we have, I. Proper directions to be observed about the right and acceptable manner of bestowing charity; and it is of great concernment that we not only do what is required, but do it as is commanded. Now, as to the manner in which the apostle would have the Corinthians give, observe, 1.

Commenting on 2 Corinthians 9:6-15

John Gill Reformed Baptist @doctorgill

And by their prayer for you,.... The sense is, they glorify God on your behalf, making mention of you in all their prayers at the throne of grace, giving thanks to God for your liberality to them, and imploring all the blessings both of the upper and nether springs upon you; and this contains another argument engaging the Corinthians to liberality, taken from the prayers...