Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) says: In the time of the Messenger of Allah (peace and blessings be upon him) we used to buy and sell in the markets, and we called ourselves brokers. But the Prophet (peace and blessings be upon him) gave us a name better than that; he (peace and blessings be upon him) said: "O company of merchants, falsehood and idle talk occur during trade, so mix it with charity."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10412