سَأَلْتُهُ عَنْ رَجُلٍ كَانَتْ لِي عَلَيْهِ مِائَةُ دِرْهَمٍ عَدَداً قَضَانِيهَا مِائَةَ دِرْهَمٍ وَزْناً قَالَ لَا بَأْسَ مَا لَمْ يَشْتَرِطْ قَالَ وَ قَالَ جَاءَ الرِّبَا مِنْ قِبَلِ الشُّرُوطِ إِنَّمَا تُفْسِدُهُ الشُّرُوطُ.
“I once asked him (the Imam) (a.s.), about the case of a man who owed me a hundred dirham in numbers and he paid me by weight. He (the Imam) said, ‘It is not unlawful if it is not stipulated . 5 He (the Imam) said, ‘Riba’ comes from stipulation; only stipulation destroys it.’”