John Chrysostom
"For if the readiness is present, it is acceptable according to what a man has, not according to what he does not have" (v. 12). What ineffable wisdom!
Earlier he noted that the Thessalonians acted beyond their strength and praised them for it, saying, "I bear witness concerning them," and, "beyond their strength." But now, when he exhorts them to give alms only according to their strength, he leaves the example of the Thessalonians to work upon them.
For he knew that, in such matters, emulation moves one to imitation more than exhortation. Therefore he says: "For if the readiness is present, it is acceptable according to what a man has, not according to what he does not have."
Read more (74 words)
"Do not be afraid," he says, "of what I said about the Thessalonians. I said this in praise of their generosity. God requires a gift according to one's strength, according to what one has, not according to what one does not have." The word "acceptable" here means the same as "required."
Trusting in the power of the example set before them, he softens his words and thereby inclines them still more strongly to give.