Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) came to us while we were buying and selling in the market, and he (peace and blessings be upon him) said: "O company of traders!" The people were delighted and turned their attention to him (peace and blessings be upon him). Before that we used to be called brokers, and he (peace and blessings be upon him) was the first to give us the name 'traders'. And he said: "Indeed, Satan and sin get mixed into buying and selling, so mix your buying and selling with charity."
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 16004