With this background...
With this background, the meaning of the following sentence becomes quite clear : “To whomsoever then the admonition has come from his Lord, then he desists, for him shall be what has already passed, and his affair rests with Allah . .
.” Even long before the verse of the third chapter, a Meccan chapter (the 30th), had condemned the practice of taking interest: And whatever you lay out as interest, so that it may increase in the properties of men, it shall not increase with Allah; and whatever you give in charity, desiring Allah’s pleasure - it is these (persons) that shall get manifold (30:39).
It shows that interest was a thing abhorred since the early days of the Call, before the hijrah; then it was clearly forbidden in the third chapter; and finally it was most forcefully condemned and denounced in these seven verses (under discussion), the style of which clearly shows that interest was forbidden long before they were revealed. It also proves that these seven verses were revealed after the third chapter.
Moreover, interest was prohibited in Judaism, as Allah says about the Jews: And their (Jews’) taking interest, though indeed forbidden were they against it (4:161); and also He says quoting them: this is because they say: there is nothing upon us in the matter of the unlearned people (3:75). Add to it the fact that the Qur’an verified their book and did not abrogate this law. All of this together was enough to make the Muslims understand that interest was prohibited and forbidden in Islam.
These verses of interest have some connection with the preceding verses of spending in the way of Allah. And this connection has been clearly pointed out in these verses: for example, “Allah effaces interest and He causes charities to grow”; “and that you remit (it) as alms is better for you”. Likewise the verse of the thirtieth chapter contrasts it with alms; and that of the third chapter is followed by praise of spending, exhorting the believers to spend benevolently in the way of Allah.
Moreover, reason also recognizes the contrast and mutual opposition of interest and charity. Interest is taking without giving anything in exchange; charity is giving without taking anything in exchange. The evils emanating from interest are poles apart from the good effects of charity.