Augustine of Hippo — as excerpted in the Catena Aurea on Matthew 5:38-42

“(ubi sup.) Therefore, He says not, ‘Give all things to him that asks;’ but, Give to every one that asketh; that you should only give what you can give honestly and rightly. For what if one ask for money to employ in oppressing the innocent man? What if he ask your consent to unclean sin? We must give then only what will hurt neither ourselves or others, as far as man can judge; and when you have refused an inadmissible request, that you may not send away empty him that asked, shew the righteousness of your refusal; and such correction of the unlawful petitioner will often be a better gift than the granting his suit.”