أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، عَنْ مَالِكٍ، وَاللَّيْثِ، - وَاللَّفْظُ لَهُ - عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " لاَ يَبِيعُ أَحَدُكُمْ عَلَى بَيْعِ أَخِيهِ " .
It was narrated from Ibn 'Umar that the Prophet said: "No one of you should urge someone to cancel a sale he has already agreed upon with his brother so as to sell him his own goods." Translation Not Available
Book Ref: Sunan An Nisai Book 44 Hadith 4503
Web Ref: Sunan An Nisai Vol 5 Book 44 Hadith 4507