Ibn ʿAbbas said, "Messenger of Allah ﷺ said, 'Do not go to meet the caravans on the way (for buying their goods without letting them know the market price); a town dweller should not sell the goods of a desert dweller on behalf of the latter.' I asked Ibn ʿAbbas, 'What does he mean by not selling the goods of a desert dweller by a town dweller?' He said, 'He should not become his broker.' "  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ تَلَقَّوُا الرُّكْبَانَ وَلاَ يَبِيعُ حَاضِرٌ لِبَادٍ قَالَ فَقُلْتُ لاِبْنِ عَبَّاسٍ مَا قَوْلُهُ لاَ يَبِيعُ حَاضِرٌ لِبَادٍ قَالَ لاَ يَكُونُ لَهُ سِمْسَارًا