The most well-known and the most central concept in Islamic economics is the prohibition of ribaa, defined as interest. All transactions in Islam must be free of ribaa. In its literal meaning, the word ribaa (raa-baa-vow) means increase or rise. For example, the root word of it is used in the Qur’an as follows:
فَإِذَا أَنزَلْنَا عَلَيْهَا الْمَاء اهْتَزَّتْ وَرَبَتْ
But when We pour down rain on it, it is stirred (to life), it swells. (Qur’an 22: 5)
In the above verse, the word rabat is used to indicate the swelling of barren and lifeless earth. Similarly Allah (SWT) says:
أَن تَكُونَ أُمَّةٌ هِيَ أَرْبَى مِنْ أُمَّةٍ
Lest one party should be more numerous than another. (Qur’an 16: 92)
In the above verse the word arbaa has also been translated as overcoming or increasing. The word can also be translated as being higher in relation to something else. In the following verse Allah (SWT) describes how Mary and her son too refuge on a higher ground by using the word rabwa:
وَجَعَلْنَا ابْنَ مَرْيَمَ وَأُمَّهُ آيَةً وَآوَيْنَاهُمَا إِلَى رَبْوَةٍ
And We made the son of Mary and his mother as a Sign: We gave them both shelter on a high ground. (Qur’an 23: 50)
The above verses make it clear that the word riba refers to an increase from the original status. This is how the term is then used in Islam with reference to interest.
Source: Mawdudi, Abul Ala. Muashiat-e-Islam. 11th ed. Karachi: Ma’araf Islami, 1986. 229-230.