A man told the Messenger of Allah (ﷺ) that he was being deceived in business transactions. The Messenger of Allah (ﷺ) then said: When you make a bargain, say: There is no attempt to deceive. So when the man made a bargain, he said: There is no attempt to deceive.
Sunan Abi Dawud Book 24, Hadith 85
← Previous Hadith I bought olive oil in the market. When I became its owner, a man met me and offered good profit for it. I intended to settle the bargain with him, but a man caught hold of my hand from behind. When I turned I found that he was Zayd ibn Thabit. He said: Do not sell it on the spot where you have bought it until you take it to your house, for the Messenger of Allah (ﷺ) forbade to sell the goods where they are bought until the tradesmen take them to their houses.

Sunan Abi Dawud Book 24, Hadith 84 Next Hadith → During the time of the Messenger of Allah (ﷺ) a man used to buy (goods), and he was weak in his intellect. His people came to the Prophet of Allah (ﷺ) and said: Prophet of Allah, stop so-and-so (to make a bargain) for he buys (goods), but he is weak in his intellect. So the Prophet (ﷺ) called on him and forbade him to make a bargain. He said: Prophet of Allah, I cannot keep away myself from business transactions. Thereupon the Messenger of Allah (ﷺ) said: If you cannot give up making a bargain , then say: Take , and give, and there is no attempt to deceive.

Sunan Abi Dawud Book 24, Hadith 86