What does "doubled and multiplied" means in the context of usury in Qur'an 3:130?

> O you who have believed, do not consume usury, doubled and multiplied, but fear Allah that you may be successful. -- Qur'an 3:130 **Question**: What does "doubled and multiplied" means in the context of usury in Qur'an 3:130? I'm unclear under what circumstances this would be meaningful. I found some tafsir, but they didn't clarify what this means, e.g.: > ... by increasing the amount to be repaid when the loan period comes to an end ... Tafsir al-Jalalayn > > ... Among this is the loaning of one thing, demanding twice as much in return, and asking from you seven hundred times its amount, ad infinitum. ... -- Al Qushairi Tafsir The latter one even reads as if only large quantities of interest are forbidden, but I don't think that's accurate.