Ibn 'Umar (RA) reported Allah's Messenger ( صلی اللہ علیہ وسلم ) as having said this: One amongst you should not enter into a transaction when another is bargaining.

Ibn 'Umar (RA) reported Allah's Messenger ( صلی اللہ علیہ وسلم ) as saying: A person should not enter into a transaction when his brother is already making a transaction and he should not make a proposal of marriage when his brother has already made a proposal except when lie gives permission.

Abu Hurairah (RA) reported Allah's Messenger ( صلی اللہ علیہ وسلم ) as saying: A Muslim should not purchase (in opposition) to his brother.

Abu Hurairah (RA) reported Allah's Messenger (may peace'be upon him) as saying: Do not go out to meet riders to enter into transaction with them; none of you must buy in opposition to another, nor must you bid against one another; a townsman must not sell for a man from the desert, and do not tie up udders of carnels and sheep, and he who buys them after that has been done has two courses open to him: after he has milked them he may keep them if he is pleased with them, or he may return them along with a sit of dates if he is displeased with them.

Abu Hurairah (RA) reported that Allah's Messenger ( صلی اللہ علیہ وسلم ) forbade the (people) meeting the caravan (for entering into business transaction with them), and the selling of goods by a townsman on behalf of a man of the desert, and seeking by a woman the divorce of her sister (from her husband), and outbidding (against one another), and tying up the udders (of animals), and buying of (things) in opposition to one's brother.

This hadith has been narrated through another chain of transmitters.

Ibn 'Umar (RA) reported that Allah's Messenger ( صلی اللہ علیہ وسلم ) forbade the outbidding (against another).