I exchanged some silver for gold with Talhah bin ‘Ubaidullah, and he said: Wait for me until our storekeeper comes from al-Ghabah, ʿUmar bin al-Khattab heard that and said: No, by Allah! Do not leave him until you take your exchange from him, for I heard the Messenger of Allah ﷺ say: ʿGold for silver is riba unless it is ʿhere, take thisʿ and ʿhere, take thisʿ [i.e., exchanged on the spot].”
أَنْظِرْنِي حَتَّى يَأْتِيَنَا خَازِنُنَا مِنَ الْغَابَةِ قَالَ فَسَمِعَهَا عُمَرُ بْنُ الْخَطَّابِ فَقَالَ لَا وَاللهِ لَا تُفَارِقُهُ حَتَّى تَسْتَوْفِيَ مِنْهُ صَرْفَهُ فَإِنِّي سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ الذَّهَبُ بِالْوَرِقِ رِبًا إِلَّا هَاءَ وَهَاءَ