(80) باب بَيْعِ الْوَرِقِ بِالذَّهَبِ نَسِيئَةً
Narrated Abu Al-Minhal:
I asked Al-Bara' bin `Azib and Zaid bin Arqam about money exchanges. Each of them said, "This is better than I," and both of them said, "Allah's Messenger (ﷺ) forbade the selling of silver for gold on credit. "
Reference: Sahih al-Bukhari 2180, 2181
In-book reference: Book 34, Hadith 129
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 34, Hadith 387