"لا يَبِيع بَعْضُكُمْ عَلَى بيعِ أخِيهِ".
See similar narrations below:
Collected by Bukhārī, Muslim, Ibn Mājah, Ḥākim, Ibn Ḥibbān, Nasāʾī's KubráMessenger of Allah ﷺ said, "Do not urge somebody to return what he has already bought (i.e. in optional sale) from another seller so as to sell him your own goods."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَبِيعُ بَعْضُكُمْ عَلَى بَيْعِ أَخِيهِ
One amongst you should not enter into a transaction when another is bargaining.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَبِعْ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَبِيعُ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ
فِي قَوْلِهِ ﷻ {وَلَا تَلْمِزُوا أَنْفُسَكُمْ} [الحجرات 11] قَالَ «لَا يَطْعُنُ بَعْضُكُمْ عَلَى بَعْضٍ»
ذِكْرُ الزَّجْرِ عَنْ بَيْعِ الْمَرْءِ عَلَى بَيْعِ أَخِيهِ قَبْلَ أَنْ يَتَفَرَّقَ الْبَائِعُ وَالْمُشْتَرِي
"Let one of you not undersell another."[1] (Using translation from Ibn Mājah 2171)
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «لَا يَبِعْ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ»
Messenger of Allah ﷺ said, "Do not urge somebody to return what he has already bought (i.e. in optional sale) from another seller so as to sell him your own goods." (Using translation from Bukhārī 2139)
عَنِ النَّبِيِّ ﷺ قَالَ «لَا يَبِيعُ أَحَدُكُمْ عَلَى بَيْعِ بَعْضٍ»