We used to go ahead to meet the caravan and used to buy foodstuff from them. The Prophet (ﷺ) forbade us to sell it till it was carried to the market.
Sahih al-Bukhari Book 34, Hadith 117
← Previous Hadith 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."

Sahih al-Bukhari Book 34, Hadith 116 Next Hadith → 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.

Sahih al-Bukhari Book 34, Hadith 118