The Messenger of Allah ﷺ forbade meeting caravans on their way to market and forbade a town-dweller selling on behalf of a desert-dweller.I asked Ibn Abbas, "What does his saying 'a town-dweller selling on behalf of a desert-dweller' mean?"He replied, "He should not act as a broker for him."
حدثنا عبد الرزاق حدثنا معمر عن ابن طاوس عن أبيه
نهى رسول الله ﷺ أن يتلقى الركبان وأن يبيع حاضر لباد قال قلت لابن عباس ما قوله حاضر لباد قال لا يكون له سمسارا
Its isnad is sahih. It was narrated by the group except Tirmidhi, with an addition at its beginning, "Do not meet the caravans," as in Al-Muntaqa 2838, and we have already referred to it at 3213, see also 4531.