Ibn ʿAbbas 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 ʿAbbas, "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."
عَنِ ابْنِ عَبَّاسٍ ؓ نَهَى رَسُولُ اللَّهِ ﷺ أَنْ يُتَلَقَّى الرُّكْبَانُ وَلاَ يَبِيعَ حَاضِرٌ لِبَادٍ قُلْتُ يَا ابْنَ عَبَّاسٍ مَا قَوْلُهُ لاَ يَبِيعُ حَاضِرٌ لِبَادٍ قَالَ لاَ يَكُونُ لَهُ سِمْسَارًا