Sayyiduna Qays bin Abi Gharazah (may Allah be pleased with him) said: In Madinah we used to be called brokers. Then the Messenger of Allah (peace and blessings be upon him) said: "O company of traders, oaths and lying get mixed into buying and selling, so mix it with charity."
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 16010