وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا هُشَيْمٌ، عَنْ يُونُسَ، عَنِ ابْنِ سِيرِينَ، عَنْ أَنَسِ، بْنِ مَالِكٍ قَالَ نُهِينَا أَنْ يَبِيعَ، حَاضِرٌ لِبَادٍ ‏.‏ وَإِنْ كَانَ أَخَاهُ أَوْ أَبَاهُ ‏.‏

Anas b. Malik (Allah be pleased with him) reported: We were forbidden that a townsman should sell for a man of the desert, even if he is his brother or father. Translation Not Available

Book Ref: Sahih Muslim Book 21 Hadith 3632
Web Ref:  Sahih Muslim Book 10 Hadith 1523 a