Sahih Bukhari 2161

Narrated Abu Huraira: The Prophet 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 forbade meeting the owners of goods on the way away from the market. ..

Narrated `Abdullah bin `Umar: Allah's Apostle 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. ..

Narrated `Abdullah: We used to go ahead to meet the caravan and used to buy foodstuff from them. The Prophet forbade us to sell it till it was carried to the market. ..

Narrated `Abdullah: Some people used to buy foodstuff at the head of the market and used to sell it on the spot. Allah's Apostle forbade them to sell it till they brought it to (their) places. ..