Let us follow Quran and Hadith:
O you who believe! Have Taqwa of Allah and give up what remains from Riba, if you are (really) believers. And if you do not do it, then take a notice of war from Allah and His Messenger. (Al Quran, 2:278-279)
Let us follow Quran and Hadith
Riba Constitutes War Against Allah and His Messenger
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(And give up what remains of Riba) meaning, abandon the Riba that people still owe you upon hearing this warning,
(if you indeed have been believers) believing in the trade that He allowed you and the prohibition of Riba
Zayd bin Aslam, Ibn Jurayj, Muqatil bin Hayyan and As-Suddi said that this Ayah was revealed about Bani `Amr bin `Umayr, a sub-tribe of Thaqif, and Bani Al-Mughirah, from the tribe of Bani Makhzum, between whom were outstanding transactions of Riba leftover from time of Jahiliyyah. When Islam came and both tribes became Muslims, Thaqif required Bani Al-Mughirah to pay the Riba of that transaction, but Bani Al-Mughirah said, “We do not pay Riba in Islam.” `Attab bin Usayd, the Prophet’s deputy on Makkah, wrote to the Messenger of Allah about this matter. This Ayah was then revealed and the Messenger of Allah conveyed it to `Attab,
(O you who believe! Be afraid of Allah and give up what remains (due to you) from Riba (from now onward), if you are (really) believers. And if you do not do it, then take a notice of war from Allah and His Messenger.)
They said, “We repent to Allah and abandon whatever is left of our Riba”, and they all abandoned it This Ayah serves as a stern threat to those who continue to deal in Riba after Allah revealed this warning.
Ibn Jurayj said that Ibn `Abbas said that,
(then take a notice of war) means, “Be sure of a war from Allah and His Messenger.” He also said, “On the Day of Resurrection, those who eat Riba will be told, `take up arms for war.”’ He then recited,
﴿فَإِن لَّمْ تَفْعَلُواْ فَأْذَنُواْ بِحَرْبٍ مِّنَ اللَّهِ وَرَسُولِهِ﴾
(And if you do not do it, then take a notice of war from Allah and His Messenger.)
`Ali bin Abi Talhah said that Ibn `Abbas said about,
﴿فَإِن لَّمْ تَفْعَلُواْ فَأْذَنُواْ بِحَرْبٍ مِّنَ اللَّهِ وَرَسُولِهِ﴾
(And if you do not do it, then take a notice of war from Allah and His Messenger,) “Whoever kept dealing with Riba and did not refrain from it, then the Muslim Leader should require him to repent. If he still did not refrain from Riba, the Muslim Leader should cut off his head.”
Allah then said,
﴿وَإِن تُبتُمْ فَلَكُمْ رُءُوسُ أَمْوَلِكُمْ لاَ تَظْلِمُونَ﴾
(But if you repent, you shall have your capital sums. Deal not unjustly) by taking the Riba,
﴿وَلاَ تُظْلَمُونَ﴾
(And you shall not be dealt with unjustly) meaning, your original capital will not diminish. Rather, you will receive only what you lent without increase or decrease. Ibn Abi Hatim recorded that `Amr bin Al-Ahwas said, “The Messenger of Allah gave a speech during the Farewell Hajj saying;
«أَلَا إِنَّ كُلَّ رِبًا كَانَ فِي الْجَاهِلِيَّةِ، مَوْضُوعٌ عَنْكُمْ كُلُّهُ، لَكُمْ رُؤُوسُ أَمْوَالِكُم لَا تَظْلِمُونَ وَلَاتُظْلَمُونَ، وَأَوَّلُ رِبًا مَوْضُوعٍ، رِبَا الْعَبَّاسِ بْنِ عَبْدِالْمُطَّلِبِ مَوْضُوعٌ كُلُّه»
(Verily, every case of Riba from the Jahiliyyah is completely annulled. You will only take back your capital, without increase or decrease. The first Riba that I annul is the Riba of Al-`Abbas bin `Abdul-Muttalib, all of it is annulled.)
*****Tafsir Ibn Kathir****
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