The Messenger of Allah (may Allah's peace and blessings be upon him) forbade riders being met on their way, and a townsman selling for a man from the desert

The Prophet (may Allah's peace and blessings be upon him) forbade certain types of transactions because they negatively impact the parties involved. 1. It is forbidden to go to meet people arriving with merchandise, in order to buy their goods before they reach the market. If those arriving do not know the market price, the transaction will be unfair to them as they could lose the real amount that they had struggled to earn. The real value of their commodity will be an easy gain for those who had not worked for it. 2. It is forbidden for a townsman to offer to keep the merchandise of a man coming from the desert to sell his wares in the town at the market value of the day and return, and sell it when prices go up. This transaction is forbidden due to the harm done to the townspeople. The laws of Islam thus protect the rights of both the unknown seller and the townspeople.