Sunan an-Nasa'i, Volume 5, Book 44, Hadith 4497 (DarusSalam) ⓘ
It was narrated from Anas that: the Prophet forbade a town-dweller to sell for a desert- dweller, even if he was his father or brother. (Sahih )
أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنِي مُحَمَّدُ بْنُ الزِّبْرِقَانِ، قَالَ حَدَّثَنَا يُونُسُ بْنُ عُبَيْدٍ، عَنِ الْحَسَنِ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم نَهَى أَنْ يَبِيعَ حَاضِرٌ لِبَادٍ وَإِنْ كَانَ أَبَاهُ أَوْ أَخَاهُ .
also referenced under: Hadith 4492 (Reference) & Book 44, Hadith 44 (In-Book)