Here, again, it is clear that faithfully to cling to the literal interpretation would be utterly to ignore the true spirit of the Lord's words here, where he sets forth his sublime ideal of a charity which ignores its own rights and knows no limits to its self-sacrifice.
Augustine quaintly suggests that in the words themselves will be found the limitation required. "'Give to every man,' but not everything,' suggesting that in many cases a medicine for the hurt of the soul would better carry out the words of the Lord than the gift of material help for the needs of the body ('Serm.' 359.). But such ingenious exposition, after all, is needless.
What the Lord inculcated here was that broad, unselfish generosity which acts as though it really believed those other beautiful words of Jesus, that "it is more blessed to give than to receive."
We must not only love our enemies, and bear a good will to them, but we must do good to them, be as ready to do any good office to them as to any other person, if their case call for it, and it be in the power of our hands to do it. We must study to make it appear, by positive acts, if there be an opportunity for them, that we bear them no malice, nor see revenge.
Do they curse us, speak ill of us, and wish ill to us? Do they despitefully use us, in word or deed? Do they endeavour to make us contemptible or odious? Let us bless them, and pray for them, speak well of them, the best we can, wish well to them, especially to their souls, and be intercessors with God for them.
[Excerpt from The Pulpit Commentary & Matthew Henry's Complete Work]