Sunan Ibn Majah 2355

Abu Bakr bin Abi Shaybah narrated to us: Abd Al-Ala narrated to us, from Muhammad bin Ishaq, from Muhammad bin Yahya bin Habban, who said: He is my grandfather, Munqidh bin Amr. He was a man who had suffered a severe wound to his head that affected his speech, yet he continued trading and was continually cheated. He went to the Prophet (peace and blessings be upon him) and told him about this. The Prophet said to him: When you make a sale, say: There is to be no deception. Then, for every item you buy, you have the option for three nights: if you are pleased, keep it; if you are displeased, return it to its owner.