سنن النسائي

Muslim bin Yasar and Abdullah bin Ubaid who was called Ibn Hurmuz narrated that 'Ubadah bin As-Samit and Muawiyah met at a stopping place on the road. 'Ubadah told them: "The Messenger of Allah (ﷺ) forbade selling gold for gold, silver for silver, dates for dates, wheat for wheat, barley for barley"- one of them said: "salt for salt," but the other did not say it-"unless it was equal amount for equal amount, like for like." One of them said: "Whoever gives more or takes more has engaged in Riba," but he other one did not say it. "And he commanded us to sell gold for silver and silver for gold, and wheat for barley and barley for wheat, hand to hand, however we wanted."