The Messenger of Allah ﷺ said, "Do not go out to meet the caravans in order to buy their goods, and let none of you outbid another on a sale already underway. Do not drive up prices for goods you have no intention of buying, and let no town dweller sell on behalf of a desert dweller. Do not withhold the milk of camels and sheep to make their udders appear full. Whoever buys such an animal after that has the better of two choices once he has milked it. If he is pleased with it, he may keep it, and if he is displeased with it, he may return it along with a measure of dates."
و حدثني مالك عن أبي الزناد عن الأعرج
أن رسول الله ﷺ قال لا تلقوا الركبان للبيع ولا يبع بعضكم على بيع بعض ولا تناجشوا ولا يبع حاضر لباد ولا تصروا الإبل والغنم فمن ابتاعها بعد ذلك فهو بخير النظرين بعد أن يحلبها إن رضيها أمسكها وإن سخطها ردها وصاعا من تمر