The prohibition of interest (a.k.a usury/riba) is a central concept of Shariah (Islamic Law) that has been agreed upon by the scholars of the religion since the birth of the religion in the 6th century.
Below are some of the references from the origional sources of legistlation in Islam, namely the Quran (Muslim’s holy book) and the Hadith (the tradition of the Prophet of Islam Muhammad, may the peace and blessing of the All Mighty be upon him).
Quran
Chapter 2:
Those who consume interest cannot stand [on the Day of Resurrection] except as one stands who is being beaten by Satan into insanity. That is because they say, “Trade is [just] like interest.” But Allah has permitted trade and has forbidden interest. So whoever has received an admonition from his Lord and desists may have what is past, and his affair rests with Allah . But whoever returns to [dealing in interest or usury] – those are the companions of the Fire; they will abide eternally therein.
Allah destroys interest and gives increase for charities. And Allah does not like every sinning disbeliever.
Indeed, those who believe and do righteous deeds and establish prayer and give zakah will have their reward with their Lord, and there will be no fear concerning them, nor will they grieve.
O you who have believed, fear Allah and give up what remains [due to you] of interest, if you should be believers.
And if you do not, then be informed of a war [against you] from Allah and His Messenger. But if you repent, you may have your principal – [thus] you do no wrong, nor are you wronged.
And if someone is in hardship, then [let there be] postponement until [a time of] ease. But if you give [from your right as] charity, then it is better for you, if you only knew. (Quran 2:275-280)
Chapter 3:
O you who have believed, do not consume usury, doubled and multiplied, but fear Allah that you may be successful. (Quran 3:129)
Chapter 4:
And [for] their taking of usury while they had been forbidden from it, and their consuming of the people’s wealth unjustly. And we have prepared for the disbelievers among them a painful punishment. (Quran 4:161)
Chapter 30:
And whatever you give for interest to increase within the wealth of people will not increase with Allah . But what you give in zakah, desiring the countenance of Allah – those are the multipliers. (Quran 30:39)
Hadith:
From Jabir : The Prophet, peace be upon him (pbuh) said: “May they be cursed, the receiver and the payer of interest, the one who records it and the two witnesses to the transaction. They are all alike [in guilt].” (From the Compilations of Muslim, Tirmidhi, and Musnad Ahmad)
Jabir ibn ‘Abdallah , giving a report on the Prophet’s Farewell Pilgrimage, said: The Prophet (pbuh) addressed people and said “All of the riba of Jahiliyyah is annulled. The first riba that I annul is our riba, that accruing to ‘Abbas ibn ‘Abd al-Muttalib [the Prophet’s uncle]; it is being cancelled completely.” (Muslim and Musnad Ahmad)
From Abu Hurayrah : The Prophet (pbuh) said: “There will certainly come a time for mankind when everyone will take riba and if he does not do so, its dust will reach him.” (Abu Dawud and Ibn Majah)
