Sunan Ibn Majah, Volume 3, Book 12, Hadith 2260 (DarusSalam) ⓘ

It was narrated that Malik bin Aws bin Hadathan said: "I came saying. 'Who will exchange Dirham?' Talhah bin 'Ubaidullah, who was with 'Umar bin Khattab, said: 'Show us your gold, then come to us; when our treasure comes, we will give you your silver.' 'Umar said: 'No, by Allah, you will give him silver (now), or give him back his gold, for the Messenger of Allah said: "Silver for gold is usury, unless it is exchanged on the spot."'

حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنِ ابْنِ شِهَابٍ، عَنْ مَالِكِ بْنِ أَوْسِ بْنِ الْحَدَثَانِ، قَالَ أَقْبَلْتُ أَقُولُ مَنْ يَصْطَرِفُ الدَّرَاهِمَ فَقَالَ طَلْحَةُ بْنُ عُبَيْدِ اللَّهِ وَهُوَ عِنْدَ عُمَرَ بْنِ الْخَطَّابِ أَرِنَا ذَهَبَكَ ثُمَّ ائْتِنَا إِذَا جَاءَ خَازِنُنَا نُعْطِكَ وَرِقَكَ ‏.‏ فَقَالَ عُمَرُ كَلاَّ وَاللَّهِ لَتُعْطِيَنَّهُ وَرِقَهُ أَوْ لَتَرُدَّنَّ إِلَيْهِ ذَهَبَهُ فَإِنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ ‏ "‏ الْوَرِقُ بِالذَّهَبِ رِبًا إِلاَّ هَاءَ وَهَاءَ ‏" ‏ ‏.‏