Cicero, De Legibus 1.18
What about generosity? Is it for free or with a view towards some benefit? If someone is kind without payment, then it is freely done. If it is for payment, it is contractual. There is no doubt that a person who is called generous or kind responds to duty not to benefit. Therefore, equity seeks no reward or purchase price but it is pursued for its own worth. This is the same cause and claim for every virtue.”
quid? liberalitas gratuitane est an mercennaria? si sine praemio benignus est, gratuita, si cum mercede, conducta; nec est dubium, quin is, qui liberalis benignusve dicitur, officium, non fructum sequatur; ergo item iustitia nihil expetit praemii, nihil pretii; per se igitur expetitur. eademque omnium virtutum causa atque sententia est.
Clement, Letter 16.4
“Giving to charity is therefore noble as repentance from sin. Fasting is stronger than prayer, but charity surpasses both. Love overcomes a mass of sins, and prayer from a noble conscience provides rescue from death. Everyone who is discovered to abound in these things is blessed. For charity lightens the weight of sin.”
καλὸν οὖν ἐλεημοσύνη ὡς μετάνοια ἁμαρτίας· κρείσσων νηστεία προσευχῆς, ἐλεημοσύνη δὲ ἀμφοτέρων· ἀγάπη δὲ καλύπτει πλῆθος ἁμαρτιῶν, προσευχὴ δὲ ἐκ καλῆς συνειδήσεως ἐκ θανάτου ῥύεται. μακάριος πᾶς ὁ εὑρεθεὶς ἐν τούτοις πλήρης· ἐλεημοσύνη γὰρ κούφισμα ἁμαρτίας γίνεται.