l brought some dinars of mine and wanted to exchange them. Talhah bin ‘Ubaidullah met me and we agreed to an exchange. Then he took them and said: Wait until my storekeeper comes - Abu ʿAmir said. From al-Ghalal (a place). And he said concerning it. All of it should be ‘Take this’ and ʿtake thisʿ [i.e., exchanged on the spot]. - I asked ‘Umar bin al-Khattab ؓ about that and he said: I heard the Messenger of Allah ﷺ say: ʿSilver for gold is riba, unless it is exchanged on the spot, wheat for wheat is riba, unless it is exchanged on the spot; barley for barley is riba, unless it is exchanged on the spot dates for dates is ribu unless it is exchanged on the spot.” (Using translation from Aḥmad 314)  

قَالَ رَسُولُ اللهِ ﷺ «الذَّهَبُ يَعْنِي بِالْوَرِقِ رِبًا إِلَّا هَاءَ وَهَاءَ وَالْبُرُّ بِالْبُرِّ رَبًّا إِلَّا هَاءَ وَهَاءَ وَالشَّعِيرُ بِالشَّعِيرِ رَبًّا إِلَّا هَاءَ وَهَاءَ وَالتَّمْرُ بِالتَّمْرِ رَبًّا إِلَّا هَاءَ وَهَاءَ»