Your source is either wrong or out of date. It wonders as to whether the Jubilee was ever implemented. There's no real reason to doubt it, as the laws were simply copied from Sumeria (the exiles returning from Babylonia) and we know that such debt relief was standard practice there for centuries (for example, there are court decisions against people ignoring it. Since the decisions were written on clay tables, they survived).

Hence my reference to Hudson. You should really read his book, but here's a recent summary on Naked Capitalism.