عَنْ طَلْحَةَ بْنِ عُبَيْدِ اللَّهِ رَضِيَ اللَّهُ عَنْهُ مِنْ حَدِيثٍ طَوِيلٍ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَدْ نَهَى أَنْ يَبِيعَ حَاضِرٌ لِبَادٍ
It is narrated from Sayyiduna Talha bin Ubaidullah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) forbade that a townsman should trade on behalf of a villager. This is a lengthy hadith.