Coke's Commentary on the Holy Bible
Deuteronomy 23:19,20
Ver. 19, 20. Thou shalt not lend upon usury to thy brother, &c.— i.e. To an Israelite. See Exodus 22:25. But though they might not lend to Israelites, they are allowed to do so to strangers; for, as nothing was more reasonable, than that their neighbours the Sidonians, Tyrians, Egyptians, and others, who made great gain by merchandise, should not borrow money of the Israelites for nothing; so was it no less reasonable, that the Israelites themselves, whose chief profit was by husbandry, and breeding of cattle, should have money lent them freely by one another without interest, their land not being a country of traffic, whereby money might be improved, as in other countries. See Grotius on Luke 6:35. A benediction, as usual, is added to the performance of this law; which, being made principally for the benefit of the poorer Israelites, as appears from Exodus 22:25 and Leviticus 25:36 is to be estimated among those duties of charity to which many promises of spiritual and temporal blessings are annexed. To this purpose Philo, in his Treatise of Humanity, says well, "The law forbids an Israelite to take usury of his brother; as thus, neither were the poor liable to be involved in inextricable straits, by being obliged to give back more than they received, nor did the lender lose his gain; for he received a valuable equivalent in the possession of those honours, and that internal applause, which generosity, good-nature, and greatness of mind, bestow." Mr. Harrington, in his Oceana, p. 245, infers from this passage, "first, that usury (by which he means lawful interest) in itself is not unlawful; and, secondly, that usury in Israel was no otherwise forbidden, than as it might come to overthrow the balance or foundation of the government: for when a lot, in general, amounted not perhaps to four acres, a man who should have had one thousand pounds in his purse, could not have regarded such a lot, in comparison of his money; and he that should have been half so much in debt, would have been quite eaten up."