"Ubadah bin Samit and Mu'awiyah happened to meet, either in a church or in a synagogue. 'Ubadah bin Samit narrated to them and said: 'The Messenger of Allah ﷺ forbade us from selling silver for silver, gold for gold, wheat for wheat, barley for barley, and dates for dates.'I one of them said: "And salt for salt," but the other did not say it. "And he commanded us to sell wheat for barley, or barley for wheat, hand-to-hand, however we wished."  

نَهَانَا رَسُولُ اللَّهِ ﷺ عَنْ بَيْعِ الْوَرِقِ بِالْوَرِقِ وَالذَّهَبِ بِالذَّهَبِ وَالْبُرِّ بِالْبُرِّ وَالشَّعِيرِ بِالشَّعِيرِ وَالتَّمْرِ بِالتَّمْرِ قَالَ أَحَدُهُمَا وَالْمِلْحِ بِالْمِلْحِ وَلَمْ يَقُلْهُ الآخَرُ وَأَمَرَنَا أَنْ نَبِيعَ الْبُرَّ بِالشَّعِيرِ وَالشَّعِيرَ بِالْبُرِّ يَدًا بِيَدٍ كَيْفَ شِئْنَا