The Homilies of St. John Chrysostom on the 2nd Epistle of St. Paul to the Corinthians
"Let each man do according as he hath purposed in his heart." (2 Corinthians 9:7)
For a man when left to himself, does a thing more readily than when compelled. Wherefore also he dwells upon this: for having said, "according as he is disposed," he added, "Not grudgingly, nor of necessity." And neither was he content with this, but he adds a testimony from Scripture also, saying,
"For God loveth a cheerful giver."
Seest thou how frequently he lays this down? "I speak not by commandment:" and, "Herein I give my advice:" and, "as a matter of bounty, and not as of extortion," and again, "not grudgingly, nor of necessity; for God loveth a cheerful giver." In this passage I am of opinion that a large [giver] is intended; the Apostle however has taken it as giving with readiness. For because the example of the Macedonians and all those other things were enough to produce sumptuousness, he does not say many things on that head, but upon giving without reluctance. For if it is a work of virtue, and yet all that is done of necessity is shorn of its reward, with reason also he labors at this point. And he does not advise merely, but also adds a prayer, as his wont is to do, saying,
(Verse 8) "And may God, that is able, fulfill all grace towards you."