Bilāl came to the Prophet (may Allah's peace and blessings be upon him) with some good Burni dates. The Prophet (may Allah's peace and blessings be upon him) was surprised at their good quality and asked him: "From where did you get these dates?" Bilāl responded: "I had some other dates of less quality so I sold two Sā‘s of them for one Sā‘ of these Barni dates (in an exchange) to let the Prophet (may Allah's peace and blessings be upon him) eat from them. The Prophet was greatly disturbed by this deal and he expressed his annoyance because any form of disobedience in his sight was the greatest calamity. So he explained himself and said: "What you did Bilāl is the prohibited usury in essence. So, never do it. If you want to exchange something of bad quality, sell it first and then buy with its money something of better quality. This is the permissible way to do this kind of transaction in order to stay away from impermissible ways.
- صحيح البخاري –الجامع الصحيح-؛ للإمام أبي عبد الله محمد بن إسماعيل البخاري، عناية محمد زهير الناصر، دار طوق النجاة، الطبعة الأولى، 1422هـ. - صحيح مسلم؛ للإمام مسلم بن الحجاج، حققه ورقمه محمد فؤاد عبد الباقي، دار عالم الكتب-الرياض، الطبعة الأولى، 1417هـ. - الإلمام بشرح عمدة الأحكام للشيخ إسماعيل الأنصاري-مطبعة السعادة-الطبعة الثانية 1392ه. - تيسير العلام شرح عمدة الأحكام-عبد الله البسام-تحقيق محمد صبحي حسن حلاق- مكتبة الصحابة- الشارقة- الطبعة العاشرة- 1426ه. - خلاصة الكلام شرح عمدة الأحكام - فيصل بن عبد العزيز بن فيصل ابن حمد المبارك الحريملي النجدي - الطبعة: الثانية، 1412 هـ - 1992 م.