Full Sharh — Sahih Muslim 4072
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
English Translation
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
Source
Sahih Muslim(صحيح مسلم)
The Book of Musaqah
Hadith Number
4072