It was narrated from Ibn 'Umar that the Prophet ﷺ 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 won goods.'
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 " .
• Sunan an-Nasa'i, 4503
• Sunan an-Nasa'i, Vol. 5, Book of Financial Transactions, Hadith 4507
• Sunan an-Nasa'i, Book of Financial Transactions, Hadith 4507