Allah is said to have revealed to the Prophet of Islam:

30:39: That which ye lay out for increase through the property of (other) people, will have no increase with Allah: but that which ye lay out for charity, seeking the Countenance of Allah, (will increase): it is these who will get a recompense multiplied.

Allah again told the Prophet:

2:275: Those who devour usury will not stand except as stand one whom the Evil one by his touch hath driven to madness. That is because they say: "Trade is like usury," but Allah hath permitted trade and forbidden usury. Those who after receiving direction from their Lord, desist, shall be pardoned for the past; their case is for Allah (to judge); but those who repeat (The offence) are companions of the Fire: They will abide therein (for ever).

2:281: And fear the Day when ye shall be brought back to Allah. Then shall every soul be paid what it earned, and none shall be dealt with unjustly.

While verses 30:39 and 2:275 were revealed in Medina, verse 2:281 is believed to have come to the Prophet when he was in the plains of Mina.

The Arabic word for usury is riba. In an attempt to clarify the true meaning of the word riba, Fathi Osman writes:

[Usury or riba in the Quran may encompass any unlawful addition to the principle when such an addition is unfair and thus harmful to the individuals and the society. As Ibn Kathir noticed in his commentary on the verse 2:275, as did other commentators and jurists, riba is one of the most difficult subjects in Islamic law, since the verse prohibiting riba, as well as what the Prophet said about riba in his sermon during the Farewell Pilgrimage, came in the last days of the Prophet’s life. As a result of this, the Companions had no opportunity to ask him about the matter, so that even Caliph Umar stated a wish that the Prophet could have given some explanations, according to a report by Ibn Hanbal. In general, riba has been related to loans involving an exploitation of the economically weak and needy borrower by the strong and wealthy lender who always gains, whereas the borrower may be merely using the money to fulfill a need of life. …

What Muhammad Asad has clarified is essential, since usury is not a name of a certain concrete material object, but of a dealing between two or more people which can be understood within historical and social circumstances. Linguistic explanation of riba as an [addition] or an [increase] cannot shed any light on the matter, since any legitimate incurrence of profit is also an increase. Relating the words [addition] or [increase] to a loan in particular may also not be sufficiently convincing, because the circumstances of the society and the dealer have to be considered, since a loan may have secured mutual free agreement, mutual gain and payments, mutual equitable benefit, social usefulness etc. …][1]

Cutting Osman’s long discourse on riba short, I draw the following inferences from it as well as from the verses of the Quran:

1. The word [riba] or [usury] denotes excessive or exploitative interest a lender charges on a loan he makes to a borrower. This is confirmed by the use of the English word [usury] for riba. Because the word [usury] denotes exorbitant interest, its practice in the United States of America is a prosecutable offence.
   

2. Charging of a normal rate of interest on loans is not riba, or usury. Which means that the Quran has not forbidden payment and receipt of a legally approved rate of interest on a loan.. Yusuf Ali’s opinion is identical to mine, for he says: [… The definition I would accept would be: undue profit made, not in the way of legitimate trade, out of loans of gold and silver, and necessary articles of food, such as wheat, barley, dates and salt (according to the list mentioned by the Holy Apostle himself). My definition would include profiteering of all kinds of, but exclude economic credit, the creature of modern banking and finance.][2]
   

That said, I now revert to the verses I have quoted above to have a one-paragraph discussion on them.

I surmise that the verses 2:275 and 30:39 were revealed to Muhammad a year or two after his arrival in Medina, which means that from the time of their revelation, payment and receipt of riba became haram or illegal for all the Muslims. How effectively Muhammad was able to enforce this prohibition on the Jews and the Pagans of Medina remains a hotly contested issue.

Now, let us read what the Prophet is believed to have said on the payment and receipt of riba in his Farewell Sermon, which he delivered about eight or nine years after his arrival in Medina.

[Interest on money has been cancelled. I am the first one to cancel all usury on behalf of my family.]

This sentence is from the text of the sermon, which Dr. Shabbir Ahmed, one of the modern-day scholars of Islam, recently posted on some internet forums. Ibn Ishaq’s reproduction of the same sentence is slightly different. According to him, the Prophet had said: [God has decreed that there is to be no usury and the usury of ‘Abbas b. “Abdu’l-Muttalib is abolished, all of it.[3]

A close reading of the text given to us by Dr. Shabbir tells us that the Prophet himself had not understood the true meaning of the word [riba], hence his concomitant use of the word [interest] with [usury] in his sermon. Ishaq’s text dispels our suspicion, for in the text he has preserved for us, we note that the Prophet had avoided the use of the word [interest]; it giving us the impression that he knew that normal interest and usury was not one and the same thing.

With the above in our mind, let us now consider what the Prophet had told his audience. He is said to have told them that he was the first one to cancel or abolish all usury of his family members or that of Abbas b. Abdul Muttalib, and that from the date of his announcement, the practice of usury became haram or illegal. This leads me to conclude:

1. until the day of his announcement, his family members, either as lenders or as borrowers, practiced usury. That they loaned money and charged exorbitant interest (riba) is probable; the force and tone of his announcement helping me to arrive at this conclusion.
   

2. Muhammad let his family members practice usury despite the fact that Allah never lagged behind in reporting their activities to him. Allah personally spied on the common people of Medina[4] as well as on his family members,[5] lest they secretly did or said such things as were not in his best interest.
   

3. Muhammad violated the Quran by allowing his family members to practice usury.
   

Now, the question is: could a flagrant violator of Allah’s instruction be a prophet?

In my judgment, Muhammad was not a prophet or an apostle; he was an imposter and a liar. He said and did things that suited his agenda, and this is evident from the text of the Quran. In the blind pursuit of his ambition, he turned Allah into a personal servant of his, often using Him for justifying what he himself could not have justified. He made Allah an accessory to his crimes. And in his fleeting moments when he felt acting like Allah, he did it without anyone ever perceiving it.

I am cataloguing his lies and crimes in my commentary to the Quran. I hope I will be able to present them to the public very soon.