(79) باب بَيْعِ الدِّينَارِ بِالدِّينَارِ نَسْأً
Narrated Abu Salih Az-Zaiyat:
I heard Abu Sa`id Al-Khudri saying, "The selling of a Dinar for a Dinar, and a Dirham for a Dirham (is permissible)." I said to him, "Ibn `Abbas does not say the same." Abu Sa`id replied, "I asked Ibn `Abbas whether he had heard it from the Prophet (ﷺ) s or seen it in the Holy Book. Ibn `Abbas replied, "I do not claim that, and you know Allah's Messenger (ﷺ) better than I, but Usama informed me that the Prophet had said, 'There is no Riba (in money exchange) except when it is not done from hand to hand (i.e. when there is delay in payment).' "
Reference: Sahih al-Bukhari 2178, 2179
In-book reference: Book 34, Hadith 128
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 34, Hadith 386