Abu Huraira (Allah be pleased with him) reported Allah's Apostle (ﷺ) as having forbidden a dweller of the town selling the merchandise of a villager or outbidding in a sale (in order that another might fall into a snare), or a person making the proposal of marriage when his brother has already made such a proposal, or entering into a transaction when his brother has already entered; and a woman asking the divorce of her sister in order to deprive her of what belongs to her. 'Amr made this addition:" The person should not purchase in opposition to his brother
قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ تَنَاجَشُوا وَلاَ يَبِعِ الْمَرْءُ عَلَى بَيْعِ أَخِيهِ وَلاَ يَبِعْ حَاضِرٌ لِبَادٍ وَلاَ يَخْطُبِ الْمَرْءُ عَلَى خِطْبَةِ أَخِيهِ وَلاَ تَسْأَلِ الْمَرْأَةُ طَلاَقَ الأُخْرَى لِتَكْتَفِئَ مَا فِي إِنَائِهَا ".
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (ﷺ) as having said this:Do not outbid in a sale in order to ensnare. No man should enter into a transaction in which his brother has already entered, and no dweller of the town should sell on behalf of the villager. And no man should make a proposal of marriage which his brother has already made and no woman should ask for the divorce of another (co-wife) in order to deprive her of what belongs to her
Abu Huraira (Allah be pleased with him) reported Allah's Messenger (ﷺ) as saying:The Muslim should not purchase in opposition to his brother, and he should not make the proposal of marriage on the proposal already made by his brother