حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ الْعَنْبَرِيُّ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، عَنْ حَبِيبٍ، أَنَّهُ سَمِعَ أَبَا الْمِنْهَالِ، يَقُولُ سَأَلْتُ الْبَرَاءَ بْنَ عَازِبٍ عَنِ الصَّرْفِ، فَقَالَ سَلْ زَيْدَ بْنَ أَرْقَمَ فَهُوَ أَعْلَمُ ‏.‏ فَسَأَلْتُ زَيْدًا فَقَالَ سَلِ الْبَرَاءَ فَإِنَّهُ أَعْلَمُ ثُمَّ قَالاَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ بَيْعِ الْوَرِقِ بِالذَّهَبِ دَيْنًا

Habib reported that he heard Abu Minhal as saying:I asked al-Bara' b. Azib about the exchange of (gold for silver or vice versa), whereupon he said: you better ask Zaid b. Arqam for he knows more than I. So I asked Zaid but he said: You better ask al-Bara' for he knows more than I. Then both of them said: Allah's Messenger (ﷺ) forbade the sale of silver for gold when payment is to be made in future