Messenger of Allah ﷺ forbade the practice of An-Najsh. (Using translation from Bukhārī 6963)  

أَنَّ النَّبِيَّ ﷺ نَهَى عَنِ النَّجْشِ  

"No tow-dweller should sell for desert-dweller, no man should outbid his brother; and no woman should ask for her sister (in faith) to be divorced so as to turn over what is in her bowl (deprive her of her share of maintenance)" (Using translation from Nasāʾī 4507)  

عَنِ النَّبِيِّ ﷺ قَالَ «لَا يَبِيعُ حَاضِرٌ لِبَادٍ وَلَا تَنَاجَشُوا وَلَا يَزِيدُ الرَّجُلُ عَلَى بَيْعِ أَخِيهِ وَلَا تَسْأَلُ الْمَرْأَةُ طَلَاقَ أُخْتِهَا لِتَسْتَكْفِئَ بِهِ مَا فِي صَحْفَتِهَا»