Gregory of Nyssa — as excerpted in the Catena Aurea on Luke 6:32-36

“(Orat. cont. usurar.) But man ought to shun that baneful anxiety with which he seeks from the poor man increase of his money and gold, exacting a profit of barren metals. Hence he adds, And lend, hoping for nothing again, &c. If a man should call the harsh calculation of interest, theft, or homicide, he will not err. For what is the difference, whether a man by digging under a wall become possessed of property, or possess it unlawfully by the compulsory rate of interest?”