The Apostle Paul
2 Corinthians 9:7ESV·traditional attribution

Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver.

John Calvin Reformed @genevareformer

7 Every one according to the purpose of his heart. As he had enjoined it upon them to give liberally, this, also, required to be added — that liberality is estimated by God, not so much from the sum, as from the disposition.

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

Every man according as he purposeth in his heart,.... Which is not to be understood of the quantity, or any set sum he has fixed upon in his mind to give; but of the quality or nature of giving; or of the manner in which he is to give: so let him give; of his own will and free choice, from his very heart; not...