Narrated Tawus:Ibn `Abbas said, "The Prophet (ﷺ) forbade the meeting of caravans (on the way) and ordained that no townsman is permitted to sell things on behalf of a bedouin." I asked Ibn `Abbas, "What is the meaning of his saying, 'No townsman is permitted to sell things on behalf of a bedouin.' " He replied, "He should not work as a broker for him
Hadith No. 2274
Sahih al Bukhari