Sahih Muslim Book - 16, Hadith - 3459

وَحَدَّثَنِى حَرْمَلَةُ بْنُ يَحْيَى أَخْبَرَنَا ابْنُ وَهْبٍ أَخْبَرَنِى يُونُسُ عَنِ ابْنِ شِهَابٍ حَدَّثَنِى سَعِيدُ بْنُ الْمُسَيَّبِ أَنَّ أَبَا هُرَيْرَةَ قَالَ 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 فِى إِنَائِهَا ».

Abu Hurairah said: "The Messenger of Allah (s.a.w) said: 'Do not artificially inflate prices; no man should outbid his brother, and no town dweller should sell on behalf of a Bedouin, and no man should propose marriage when his brother has already proposed, and no woman should ask for her sister to be divorced so as to deprive her of what is rightfully hers and take it for herself."'