Vincent's NT Word Studies
27. Put (balein). Lit., throw or fling down, as one would throw a bag of coin upon the exchanger's table.Exchangers (trapezitaiv). Taking their name from the table or counter at which they sat (trapeza). The Jewish bankers bore precisely the same name.
Usury (tokw). A very graphic word, meaning first childbirth, and then offspring. Hence of interest, which is the product or offspring of capital. Originally it was only what was paid for the use of money; hence usury; but it became synonymous with extortionate interest. Rev., better, with interest. The Jewish law distinguished between interest and increase. In Rome very high interest seems to have been charged in early times. Practically usury was unlimited. It soon became the custom to charge monthly interest at one per cent a month. During the early empire legal interest stood at eight per cent, but in usurious transactions it was lent at twelve, twenty-four, and even forty-eight. The Jewish bankers of Palestine and elsewhere were engaged in the same undertakings. The law of Moses denounced usury in the transactions of Hebrews with Hebrews, but permitted it in dealing with strangers (Deut. xxiii. 19, 20; Psalms xv. 5).
Robertson's NT Word Studies
25:27 {Thou oughtest therefore} (edsi se oun). His very words of excuse convict him. It was a necessity (edei) that he did not see. {The bankers} (tois trapezeitais). The benchers, money-changers, brokers, who exchanged money for a fee and who paid interest on money. Word common in late Greek. {I should have received back} (eg" ekomisamn an). Conclusion of a condition of the second class (determined as unfulfilled). The condition is not expressed, but it is implied. "If you had done that." {With interest} (sun tokwi). Not with "usury" in the sense of extortion or oppression. Usury only means "use" in itself. The word is from tiktw, to bring forth. Compound interest at six per cent doubles the principal every twenty years. It is amazing how rapidly that piles up if one carries it on for centuries and millenniums. "In the early Roman Empire legal interest was eight per cent, but in usurious transactions it was lent at twelve, twenty-four, and even forty-eight" (Vincent). Such practices exist today in our cities. The Mosaic law did not allow interest in dealings between Hebrews, but only with strangers (#De 23:19,20; Ps 15:5).