Narrated Abu Huraira
The Prophet (ﷺ) forbade the meeting (of caravans) on the way and the selling of goods by an inhabitant of the town on behalf of a desert dweller.
Narrated Tawus
I asked Ibn `Abbas, "What is the meaning of, 'No town dweller should sell (or buy) for a desert dweller'?" Ibn `Abbas said, "It means he should not become his broker."
Narrated `Abdullah
Whoever buys an animal which has been kept unmilked for a long time, could return it, but has to pay a Sa of dates along with it. And the Prophet (ﷺ) forbade meeting the owners of goods on the way away from the market.
Narrated `Abdullah bin `Umar
Allah's Messenger (ﷺ) said, "You should not try to cancel the purchases of one another (to get a benefit thereof), and do not go ahead to meet the caravan (for buying the goods) (but wait) till it reaches the market."