(71) باب النَّهْىِ عَنْ تَلَقِّي الرُّكْبَان
Narrated Tawus:
I asked Ibn `Abbas, "What is the meaning of, 'No town dweller should sell (or buy) for a desert dweller'?" Ibn `Abbas said, "It means he should not become his broker."
Reference: Sahih al-Bukhari 2163
In-book reference: Book 34, Hadith 114
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 34, Hadith 372