Usury is hard to define today as wrong unless it’s excessive because global inflation and the rise in prices makes it necessary to charge interest unless it’s a really short term loan. Usury was wrong in former times because money held its value so a long term loan didn’t hurt the lender. Today, $20 will buy 5 gallons of milk. 5 years ago, the same $20 would buy 7 gallons. Due to the loss of money value, interest is necessary. In my opinion, an example of usury today are credit card rates, such as 15% or higher.