Sayyidina Anas reported that a man who traded often always ended up deceived. The people of his house met the Prophet and said, “0 Messenger of Allah, forbid him from committing any transaction.” So, he summoned him and disallowed him to trade, but he said, ‘0 Messenger of Allah I cannot endure without engaging in trade.” The Prophet said, ‘Say when you engage in buying and selling this is a transaction on equal terms and there is no fraud or deceiving.”
[Abu Dawud 3501, Nisai 4492]