صحيح مسلم

Abu Salih reported: I heard Abu Sa'id al-Khudri (Allah be pleased with him) said: Dinar (gold) for gold and dirham for dirham can be (exchanged) with equal for equal; but he who gives more or demands more in fact deals in interest. I sald to him: Ibn 'Abbas (Allah be pleased with them) says otherwise, whereupon he said: I met Ibn 'Abbas (Allah be pleased with them) and said: Do you see what you say; have you heard it from Allah's Messenger (ﷺ), or found it in the Book of Allah, the Glorious and Majestic? He said: I did not hear it from Allah's Messenger (ﷺ). and I did not find it in the Book of Allah (Glorious and Majestic), but Usama b. Zaid narrated it to me that Allah's Messenger (ﷺ) said: There can be an element of interest in credit.